Handle the first release of a gem with RELEASE_TYPE 'first'

[jcouball]

Handle the use case where this is the first release/

For this use case, let's assume the following:

• the default branch is main (this is the HEAD branch returned by git remote show origin)
• the current version of the gem is 0.1.0 (as returned by bump current)

If a different first version number is desired, update the version number in the
source code making sure that bump current returns the desired version number.
Then commit the change to the default branch on the remote before running this
script.

If you want to add custom frontmatter to your changelog file, see
How the changelog is updated. Any change
should be committed and merged/pushed to the default branch on the remote before
running this script.

The following prerequisites are checked by this script:

• The current directory must be in the top level of the git repository
• The HEAD commit of the default branch (main) must be checked out
• The HEAD commit of the default branch of the local repository must match the
  HEAD commit of the default branch of the remote repository
• There are no uncommitted or unstaged changes
• The bundle must be up to date (the script will attempt to update the bundle if needed)
• The next-release tag (v0.1.0) must NOT already exist
• The next-release branch (release-v0.1.0) must NOT already exist
• The gh command must be installed and authenticated via gh auth

You should run:

create-github-release first

The create-github-release script will do the following:

• Determine the next-release version (v0.1.0) using bump current
• Update the project's changelog file CHANGELOG.md
• Create a release branch release-v0.1.0
• Commit the changes to the changelog and create a release tag (v0.1.0) pointing
  to that commit
• Push the release branch to GitHub
• Create a GitHub release and pull request for the release

[codeclimate]

Code Climate has analyzed commit ab3e592 and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (50% is the threshold).

This pull request will bring the total coverage in the repository to 100.0% (0.0% change).

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