docs: camelcase it like GitHub everywhere

Closes #6979

.github/CONTRIBUTING.md

@@ -4,7 +4,7 @@ How to contribute to curl
 Join the community
 ------------------
 
- 1. Click 'watch' on the github repo
+ 1. Click 'watch' on the GitHub repo
 
  2. Subscribe to the suitable [mailing lists](https://curl.se/mail/)
 

docs/CONTRIBUTE.md

@@ -20,7 +20,7 @@ Before posting to one of the curl mailing lists, please read up on the
 We also hang out on IRC in #curl on irc.freenode.net
 
 If you're at all interested in the code side of things, consider clicking
-'watch' on the [curl repo on github](https://github.com/curl/curl) to be
+'watch' on the [curl repo on GitHub](https://github.com/curl/curl) to be
 notified of pull requests and new issues posted there.
 
 ### License and copyright
@@ -129,7 +129,7 @@ verified your changes.
 ### How to get your changes into the main sources
 
 Ideally you file a [pull request on
-github](https://github.com/curl/curl/pulls), but you can also send your plain
+GitHub](https://github.com/curl/curl/pulls), but you can also send your plain
 patch to [the curl-library mailing
 list](https://curl.se/mail/list.cgi?list=curl-library).
 

docs/GOVERNANCE.md

@@ -131,7 +131,7 @@ within the area of personal expertise and experience.
 
 ### Recommendations
 
-- we require two-factor authentication enabled on your github account to
+- we require two-factor authentication enabled on your GitHub account to
   reduce risk of malicious source code tampering
 - consider enabling signed git commits for additional verification of changes
 
@@ -142,7 +142,7 @@ When you're merging patches/PRs...
 - make sure the commit messages follow our template
 - squash patch sets into a few logical commits even if the PR didn't, if
   necessary
-- avoid the "merge" button on github, do it "manually" instead to get full
+- avoid the "merge" button on GitHub, do it "manually" instead to get full
   control and full audit trail (github leaves out you as "Committer:")
 - remember to credit the reporter and the helpers!
 

docs/HISTORY.md

@@ -257,7 +257,7 @@ January: Added support for RTSP
 
 February: security vulnerability: libcurl data callback excessive length
 
-March: The project switched over to use git (hosted by github) instead of CVS
+March: The project switched over to use git (hosted by GitHub) instead of CVS
 for source code control
 
 May: Added support for RTMP

docs/RELEASE-PROCEDURE.md

@@ -44,7 +44,7 @@ in the curl-www repo
 
   (the website then updates its contents automatically)
 
-on github
+on GitHub
 ---------
 
 - edit the newly made release tag so that it is listed as the latest release