Fix moderation policy moved links (master -> main)

[MikeMcC399]

Situation

In the document Moderation-Policy.md

links

• https://github.com/nodejs/admin/blob/master/CODE_OF_CONDUCT.md
• https://github.com/nodejs/admin/blob/master/GITHUB_ORG_MANAGEMENT_POLICY.md
• https://github.com/nodejs/admin/blob/master/MemberExpectations.md

do not redirect to the main branch when the document is viewed in a web browser. The master branch was renamed to main some years ago.

The GitHub UI does however redirect after clicking on "Try reloading the page".

Change

Change links to:

• https://github.com/nodejs/admin/blob/main/CODE_OF_CONDUCT.md
• https://github.com/nodejs/admin/blob/main/GITHUB_ORG_MANAGEMENT_POLICY.md
• https://github.com/nodejs/admin/blob/main/MemberExpectations.md

[aduh95]

nit: we would usually use HEAD instead in case the default branch name were to change again

[MikeMcC399]

nit: we would usually use HEAD instead in case the default branch name were to change again

A search in all *.md documents in the repo reveals that there is a mixture of master / main / HEAD used.

Possibly all the documents should be harmonized to use HEAD.

I suggest though to land this one first, as a quick fix.