With Renovate’s github platform code now using git for all file system operations, we need to tell Renovate which gitAuthor to use.

If you had already configured a gitAuthor in your bot config, you do not need to make any change.

Otherwise, to keep functionality as before, you should either:
(1) configure `gitAuthor` to match the bot’s account, or
(2) recreate your bot’s personal access token to include the “user:email” permission so that the bot can retrieve the email itself

BREAKING CHANGE: GitHub bot admins should either configure gitAuthor in their config or generate a new token with “user:email” permissions.

feat: unify file locations

Document how to sign gitFs commits, remove the disabling of gpg signing.

Closes #3053, Closes #3472

Closes #2482 

Rename all VSTS references to be Azure DevOps.

Closes #2810

BREAKING CHANGE: 'vsts' platform is now renamed to 'azure'

Deprecate use of “special” env var like `GITHUB_TOKEN` and instead standardize on `RENOVATE_*` environment variables instead.

Closes #2834

BREAKING CHANGE: For GitHub, GitLab, Bitbucket and VSTS you need to migrate `*_ENDPOINT` to `RENOVATE_ENDPOINT`, `*_TOKEN` to `RENOVATE_TOKEN`, and same for `BITBUCKET_USERNAME` and `BITBUCKET_PASSWORD`.

Adds platform support for Bitbucket cloud.

Closes #136, Closes #2238

Added content as suggested/contributed by @swashata.

Closes https://github.com/renovatebot/config-help/issues/71

Updates renovateapp -> renovatebot

docs: fix wrong url

The link to the configuration docs was broken. Fixed it.