Skip adding comment on solo PR's

[stoopkidddd]

Going to take a stab at making a PR for this, but wanted to put an issue up first.

It would be nice if there was a config option to tell the github action not to add a stack to the description if the PR isn't actually part of a stack, but just a solo PR pointing to the trunk by itself with no children

There are other people on my team not stacking their PR's, and having the comment added to their solo PRs is very confusing and does not lend to an opt-in approach.

Config option proposal - skipSinglePR: boolean added in config.ts -> configSchema

[tranhl]

@stoopkidddd Thanks for the suggestion! I can definitely see how always printing the stack can be confusing for other team members who don't stack their PRs.

Adding this feature will involve:

• Add add an input to toggle the feature in action.yml. We could call it something like skip-(single|solo)-(stacks|changes)
• Provide a getter for the input in inputs.ts: getSkipSoloChanges()
• Check this flag & the stack graph before updating the visualization in main.ts:104.

PRs are very much welcome, so if you feel up for the task by all means submit one!