[distrib] Only excludes the entire /doc directory in the distributed archive.

No more exception is needed as /doc/code is no longer used to generate the html
API documentation.

.gitattributes

@@ -9,13 +9,7 @@ Changelog merge=union
 # DISTRIBUTION #
 ################
 
-/CLA.pdf export-ignore
-/share/libc/*.pdf export-ignore
 /doc/** export-ignore
-/doc/code -export-ignore
-/doc/code/* -export-ignore
-/doc/Makefile -export-ignore
-/doc/README -export-ignore
 
 ##################################################
 # BINARY/CHECK-SYNTAX/INDENT/EOL-EOF: set/-unset #