add link to coqdoc (#1034)

* add link to coqdoc

Author: affeldt-aist

README.md

@@ -79,7 +79,8 @@ own risk.
 
 ## Documentation
 
-Each file is documented in its header.
+Each file is documented in its header
+([coqdoc presentation for the last version](https://math-comp.github.io/analysis/htmldoc_0_6_5/index.html)).
 
 Changes are documented in [CHANGELOG.md](CHANGELOG.md) and
 [CHANGELOG_UNRELEASED.md](CHANGELOG_UNRELEASED.md).