docs/RELEASE-PROCEDURE.md: renamed to use .md extension

Closes #2663

docs/Makefile.am

@@ -40,13 +40,45 @@ DIST_SUBDIRS = $(SUBDIRS) examples libcurl
 
 CLEANFILES = $(GENHTMLPAGES) $(PDFPAGES) $(MANDISTPAGES) curl.1
 
-EXTRA_DIST = MANUAL BUGS CONTRIBUTE.md FAQ FEATURES INTERNALS.md SSLCERTS.md    \
- README.win32 RESOURCES TODO TheArtOfHttpScripting THANKS VERSIONS KNOWN_BUGS   \
- BINDINGS.md HISTORY.md INSTALL INSTALL.md LICENSE-MIXING.md     \
- README.netware MAIL-ETIQUETTE HTTP-COOKIES.md SECURITY-PROCESS.md RELEASE-PROCEDURE    \
- SSL-PROBLEMS.md HTTP2.md ROADMAP.md CODE_OF_CONDUCT.md CODE_STYLE.md           \
- CHECKSRC.md CMakeLists.txt README.md CIPHERS.md INSTALL.cmake README.cmake     \
- $(noinst_man_MANS) HELP-US.md GOVERNANCE.md
+EXTRA_DIST =                                    \
+ $(noinst_man_MANS)                             \
+ BINDINGS.md                                    \
+ BUGS                                           \
+ CHECKSRC.md                                    \
+ CIPHERS.md                                     \
+ CMakeLists.txt                                 \
+ CODE_OF_CONDUCT.md                             \
+ CODE_STYLE.md                                  \
+ CONTRIBUTE.md                                  \
+ FAQ                                            \
+ FEATURES                                       \
+ GOVERNANCE.md                                  \
+ HELP-US.md                                     \
+ HISTORY.md                                     \
+ HTTP-COOKIES.md                                \
+ HTTP2.md                                       \
+ INSTALL                                        \
+ INSTALL.cmake                                  \
+ INSTALL.md                                     \
+ INTERNALS.md                                   \
+ KNOWN_BUGS                                     \
+ LICENSE-MIXING.md                              \
+ MAIL-ETIQUETTE                                 \
+ MANUAL                                         \
+ README.cmake                                   \
+ README.md                                      \
+ README.netware                                 \
+ README.win32                                   \
+ RELEASE-PROCEDURE.md                           \
+ RESOURCES                                      \
+ ROADMAP.md                                     \
+ SECURITY-PROCESS.md                            \
+ SSL-PROBLEMS.md                                \
+ SSLCERTS.md                                    \
+ THANKS                                         \
+ TODO                                           \
+ TheArtOfHttpScripting                          \
+ VERSIONS
 
 MAN2HTML= roffit $< >$@