add documentation on rawlatex

.compose-gitlab-ci.yml

@@ -22,7 +22,9 @@ buildrawlatex:
   # We recommend NOT to use this feature and only rely on org.
   # However, it is still possible to handle raw latex files,
   # may they be basic latex ones or beamer ones.
-  # Convention: we assume they are all under ./rawlatex
+  # Conventions:
+  # - we assume all the latex file are (exactly) in a ./rawlatex directory
+  # - the job for processing all the latex files is triggered only if there exists a ./rawlatex/README.org file
   stage: build
   tags: ['guix']
   script: