Add release notes for v2.3.2.

docs/release-notes/SUMMARY.md

+- [v2.3.2](v2.3.2.md)
 - [v2.3.1](v2.3.1.md)
 - [v2.3.0](v2.3.0.md)
 - [v2.2.2](v2.2.2.md)

docs/release-notes/v2.3.2.md

+# declearn v2.3.2
+
+Released: 05/10/2023
+
+This is a subminor release that patches extra dependency specifiers for Torch.
+
+## Revise Torch extra dependency specifiers and version support
+
+The rules for the "torch", "torch1" and "torch2" extra dependency specifiers
+were updated in order to be simpler and support the newest Torch 2.1 version.
+As a trade off, support for older Torch versions 1.10 to 1.12 was dropped, due
+to functorch being shipped together with versions >=1.13, enabling to remove
+the burden of having to clumsily specify for it (in spite of it no longer being
+used starting with version 2.0).
+
+The opacus dependency is back to being specified merely by the "dp" extra
+specifier, which may be updated (either independently from or together with)
+"torch" in the future - and may also be specified freely by declearn-depending
+packages, starting with Fed-BioMed.