add docs to sdist

Author: maxbachmann

CHANGELOG.md

@@ -1,5 +1,9 @@
 ## Changelog
 
+### [unreleased] - 
+#### Added
+- added docs to sdist
+
 ### [2.13.4] - 2022-12-08
 #### Changed
 - handle `float("nan")` similar to None for query / choice, since this is common for

MANIFEST.in

@@ -12,6 +12,7 @@ recursive-include src/rapidfuzz CMakeLists.txt
 recursive-include cmake *
 recursive-include src/rapidfuzz *.hpp *.h *.cpp *.cxx *.pyx *.pxd *.incl *.impl
 recursive-include tests *
+recursive-include docs *
 include src/rapidfuzz/__init__.pxd
 include src/rapidfuzz/rapidfuzz.h