Implement optional manifest update

[DarkFighterLuke]

This PR introduces a new optional parameter to update the manifest.json with the plugin release just built.
The default behavior is to not update the manifest, just like now.

This PR addresses #176

[sonarqubecloud]

Quality Gate passed

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See analysis details on SonarCloud

[oddstr13]

I'll get around to reviewing (and testing) this eventually, but for now, you should be able to just use your own fork.

Alternatively, there is nothing preventing you from installing jprm and running these commands directly in your plugin's CI.

[oddstr13]

After having taken a closer look at your implementation here, I've decided that this isn't generic enough, as it expects a very specific repository setup.

I'll eventually get around to implementing a version that satisfies my desired requirements, but it isn't high on my priority list at the moment.

For now, I suggest that people either pip install JPRM in a script action and implement the required logic there, or use your branch directly (pin to commit hash).