Improve README and rename to README.md to use GitLab Markdown

README.md

+# ScalFMM: Fast Multipole Method
+
+----
+
+:warning: ScalFMM has moved to Inria's GitLab: https://gitlab.inria.fr/solverstack/ScalFMM
+
+----
+
+**ScalFMM** is a C++ library that implements a kernel independent Fast Multipole Method.
+
+
+Copyright Inria, please read the licence.
+
+### Requirements
+
+  - CMake v2.8.12 or later
+  - C++ compiler that supports
+    - C++14 [compiler support list](http://en.cppreference.com/w/cpp/compiler_support)
+    - [OpenMP](http://www.openmp.org/resources/openmp-compilers/)
+
+The following are optional:
+
+  - [Doxygen](http://www.stack.nl/~dimitri/doxygen/) to build the documentation.
+  - An MPI implementation to build the distributed files.
+  - Custom BLAS, FFT implementations.
+  - [StarPU](http://starpu.gforge.inria.fr/) for the relevant FMM implementations.
+
+### Build
+
+``` bash
+# Move to the build folder
+cd scalfmm/Build
+# Use cmake, with relevant options
+cmake .. # -DSCALFMM_USE_MPI=ON
+```
+
+The build may be configured after the first CMake invocation using, for instance, `ccmake` or `cmake-gui`.
+
+```bash
+# Still in the Build folder
+ccmake .
+# Or
+cmake-gui .
+```
+
+The binaries are then compiled calling `make`. They can be found in `scalfmm/Build/Tests/{Release,Debug}/...`
+
+An example build using StarPU:
+
+```bash
+cmake .. -DSCALFMM_USE_STARPU=ON -DSCALFMM_USE_CUDA=OFF -DSCALFMM_USE_OPENCL=OFF  \
+               -DHWLOC_DIR=/home/berenger/Download/hwloc-1.10.0/install/      \
+               -DSTARPU_DIR=/home/berenger/Download/starpu-work/StarPU/installwithfxt
+```
+
+
+#### Build the doc:
+
+```bash
+cd scalfmm/Build
+cmake .. -DSCALFMM_BUILD_DOC=ON # or if cmake has already been called, ccmake .
+make doc
+```
+
+This will generate the documentation in HTML format in the `Build/Doc/html` folder. You can create a local server to access it using Python
+
+```bash
+# From the Build folder
+cd Doc/html
+python3 -m http.server # or python2 -m SimpleHTTPServer
+```
+
+The documentation can then be accessed from an internet browser at the address `localhost:8000`.
+
+
+### Help and News
+
+You can subscribe to the scalfmm-public-users@lists.gforge.inria.fr mailing list (http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/scalfmm-public-users). The list is very low trafic (~ 2 mails per year), we will let you know of improvements and releases.
+
+Contact the developers at : scalfmm-public-support@lists.gforge.inria.fr
+
+### Folder structure
+  - Src : library core.
+  - Data : particle distribution examples.
+  - Examples : common usage examples.
+  - Doc : documentation configuration.
+  - UTests : unit tests.
+  - Tests : examples to know how to use scalfmm/put particles in the tree/iterate on the tree...
+  - Utils : some scripts and binaries to handle data files.
+

README.txt

-
-ScalFmm, Inria, Please read the licence.
-
----------------------------------------------------
----------------------------------------------------
-
-/!\ ScalFMM has moved to Inria's GitLab: https://gitlab.inria.fr/solverstack/ScalFMM
-
-To compile:
-==========
-# Go to 
-cd scalfmm/Build
-# Use cmake first by
-cmake ..
-# Or if you want to use MPI
-cmake .. -DSCALFMM_USE_MPI=ON
-
-
-# Configure, for example with:
-ccmake ..
-# turn on/off the options you want
-# For example, it is advised to build the tests and have a look in scalfmm/Tests/
-# Finally you can build by
-make
-# And access executables in scalfmm/Build/Tests/{Release,Debug}/.....
-
-To compile with StarPU you can pass, as an example:
-cmake .. -DSCALFMM_USE_STARPU=ON -DSCALFMM_USE_CUDA=OFF -DSCALFMM_USE_OPENCL=OFF  \
-               -DHWLOC_DIR=/home/berenger/Download/hwloc-1.10.0/install/      \
-               -DSTARPU_DIR=/home/berenger/Download/starpu-work/StarPU/installwithfxt
-
-
----------------------------------------------------
----------------------------------------------------
-
-Build the doc:
-=============
-In scalfmm/Doc you can find several pdf and .tex file about
-the implementation, kernels and data structure.
-
-# The developer documentation is generated using DOxygen: 
-cd scalfmm/Build
-cmake .. -DSCALFMM_BUILD_DOC=ON
-# Tape 
-make doc
-# This will create a Html dir
-browser scalfmm/Build/Doc/html/index.html
-
-
----------------------------------------------------
----------------------------------------------------
-
-Getting help and having news from us:
-====================================
-
-You can subscribe to the scalfmm users mailing list ( scalfmm-public-users@lists.gforge.inria.fr,  http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/scalfmm-public-users ). Very low trafic (~ 2 mails per year) just to know when a new version or an improvement is available.
-
-Contact the developers at : scalfmm-public-support@lists.gforge.inria.fr
-
-
----------------------------------------------------
----------------------------------------------------
-
-What inside :
-=============
-- Src : The Core of Scalfmm is under the Src directory. Users should not need to modify the source.
-One can want to implement its own kernel or even its own parallelization whithout modifying the sources.
-- Data : example of particles distributions
-- Examples : examples of very common usage of Scalfmm
-- Doc : should contains the generated Doc
-- UTests : contains some unit tests (it can be a good example to understand some features)
-- Tests : examples to know how to use scalfmm/put particles in the tree/iterate on the tree...
-- Utils : some scripts to work with the data files.
-
-
----------------------------------------------------
----------------------------------------------------
-Concerning the 1.3 to 1.4 API update:
-=====================================
-For example the previous M2L interface was:
-void M2L(CellClass* const FRestrict inLocal, const CellClass* inInteractions[], const int /*inSize*/, const int inLevel) {
-
-But the new one is:
-void M2L(CellClass* const FRestrict inLocal, const CellClass* inInteractions[],
- const int neighborPositions[], const int inSize, const int inLevel) override {
-
-In the previous version we were iterating by
-for(int idxNeigh = 0 ; idxNeigh < 343 ; ++idxNeigh){
- // if interaction exits
- if(inInteractions[idxNeigh]){
-     inInteractions[idxNeigh]
-
-
-In the new one we do it by
-for(int idxExistingNeigh = 0 ; idxExistingNeigh < inSize ; ++idxExistingNeigh){
- const int idxNeigh = neighborPositions[idxExistingNeigh];
- inInteractions[idxExistingNeigh]