Normalize case: Github -> GitHub (#13828)

content/en/docs/contribute/participating.md

@@ -96,16 +96,16 @@ in the Kubernetes organization. Follow these steps:
       SIG Docs member.
       {{< /note >}}
 
-2.  Open a Github issue in the `kubernetes/org` repository to request membership.
+2.  Open a GitHub issue in the `kubernetes/org` repository to request membership.
     Fill out the template using the guidelines at
     [Community membership](https://github.com/kubernetes/community/blob/master/community-membership.md).
 
-3.  Let your sponsors know about the Github issue, either by at-mentioning them
-    in the Github issue (adding a comment with `@<Github-username>`) or by sending them the link directly,
+3.  Let your sponsors know about the GitHub issue, either by at-mentioning them
+    in the GitHub issue (adding a comment with `@<GitHub-username>`) or by sending them the link directly,
     so that they can add a `+1` vote.
 
 4.  When your membership is approved, the github admin team member assigned to your request updates the
-    Github issue to show approval and then closes the Github issue.
+    GitHub issue to show approval and then closes the GitHub issue.
     Congratulations, you are now a member!
 
 If for some reason your membership request is not accepted right away, the
@@ -116,7 +116,7 @@ again.
 
 Reviewers are members of the
 [@kubernetes/sig-docs-pr-reviews](https://github.com/orgs/kubernetes/teams/sig-docs-pr-reviews)
-Github group. See [Teams and groups within SIG Docs](#teams-and-groups-within-sig-docs).
+GitHub group. See [Teams and groups within SIG Docs](#teams-and-groups-within-sig-docs).
 
 Reviewers review documentation pull requests and provide feedback on proposed
 changes.
@@ -158,14 +158,14 @@ will assign and suggest you as a reviewer on new pull requests.
 
 If you are approved, request that a current SIG Docs approver add you to the
 [@kubernetes/sig-docs-pr-reviews](https://github.com/orgs/kubernetes/teams/sig-docs-pr-reviews)
-Github group. Only members of the `kubernetes-website-admins` Github group can
-add new members to a Github group.
+GitHub group. Only members of the `kubernetes-website-admins` GitHub group can
+add new members to a GitHub group.
 
 ### Approvers
 
 Approvers are members of the
 [@kubernetes/sig-docs-maintainers](https://github.com/orgs/kubernetes/teams/sig-docs-maintainers)
-Github group. See [Teams and groups within SIG Docs](#teams-and-groups-within-sig-docs).
+GitHub group. See [Teams and groups within SIG Docs](#teams-and-groups-within-sig-docs).
 
 Approvers have the ability to merge a PR, and thus, to publish content on the
 Kubernetes website. To approve a PR, an approver leaves an `/approve` comment on
@@ -198,12 +198,12 @@ will assign and suggest you as a reviewer on new pull requests.
 
 If you are approved, request that a current SIG Docs approver add you to the
 [@kubernetes/sig-docs-maintainers](https://github.com/orgs/kubernetes/teams/sig-docs-maintainers)
-Github group. Only members of the `kubernetes-website-admins` Github group can
-add new members to a Github group.
+GitHub group. Only members of the `kubernetes-website-admins` GitHub group can
+add new members to a GitHub group.
 
 #### Becoming a website admin
 
-Members of the `kubernetes-website-admins` Github group can manage Github group
+Members of the `kubernetes-website-admins` GitHub group can manage GitHub group
 membership and have full administrative rights to the settings of the repository,
 including the ability to add, remove, and troubleshoot webhooks. Not all SIG
 Docs approvers need this level of access.
@@ -232,16 +232,16 @@ for the current list of chairpersons.
 ## SIG Docs teams and automation
 
 Automation in SIG Docs relies on two different mechanisms for automation:
-Github groups and OWNERS files.
+GitHub groups and OWNERS files.
 
-### Github groups
+### GitHub groups
 
-The SIG Docs group defines two teams on Github:
+The SIG Docs group defines two teams on GitHub:
 
  - [@kubernetes/sig-docs-maintainers](https://github.com/orgs/kubernetes/teams/sig-docs-maintainers)
  - [@kubernetes/sig-docs-pr-reviews](https://github.com/orgs/kubernetes/teams/sig-docs-pr-reviews)
 
-Each can be referenced with their `@name` in Github comments to communicate with
+Each can be referenced with their `@name` in GitHub comments to communicate with
 everyone in that group.
 
 These teams overlap, but do not exactly match, the groups used by the automation
@@ -251,7 +251,7 @@ the automation uses information from OWNERS files.
 ### OWNERS files and front-matter
 
 The Kubernetes project uses an automation tool called prow for automation
-related to Github issues and pull requests. The
+related to GitHub issues and pull requests. The
 [Kubernetes website repository](https://github.com/kubernetes/website) uses
 two [prow plugins](https://github.com/kubernetes/test-infra/blob/master/prow/plugins.yaml#L210):
 
@@ -261,7 +261,7 @@ two [prow plugins](https://github.com/kubernetes/test-infra/blob/master/prow/plu
 These two plugins use the
 [OWNERS](https://github.com/kubernetes/website/blob/master/OWNERS) and
 [OWNERS_ALIASES](https://github.com/kubernetes/website/blob/master/OWNERS_ALIASES)
-files in the top level of the `kubernetes/website` Github repository to control
+files in the top level of the `kubernetes/website` GitHub repository to control
 how prow works within the repository.
 
 An OWNERS file contains a list of people who are SIG Docs reviewers and
@@ -271,7 +271,7 @@ descendents. For more information about OWNERS files in general, see
 [OWNERS](https://github.com/kubernetes/community/blob/master/contributors/guide/owners.md).
 
 In addition, an individual Markdown file can list reviewers and approvers in its
-front-matter, either by listing individual Github usernames or Github groups.
+front-matter, either by listing individual GitHub usernames or GitHub groups.
 
 The combination of OWNERS files and front-matter in Markdown files determines
 the advice PR owners get from automated systems about who to ask for technical