Tsfmt Maven Plugin for Spotless

[source-knights]

Adding the tsfmt as a Maven Plugin.

Please make sure that your PR allows edits from maintainers. Sometimes its faster for us to just fix something than it is to describe how to fix it.

After creating the PR, please add a commit that adds a bullet-point under the -SNAPSHOT section of CHANGES.md, plugin-gradle/CHANGES.md, and plugin-maven/CHANGES.md which includes:

• a summary of the change
• either
  • a link to the issue you are resolving (for small changes)
  • a link to the PR you just created (for big changes likely to have discussion)

If your change only affects a build plugin, and not the lib, then you only need to update the CHANGES.md for that plugin.

If your change affects lib in an end-user-visible way (fixing a bug, updating a version) then you need to update CHANGES.md for both the lib and the build plugins. Users of a build plugin shouldn't have to refer to lib to see changes that affect them.

This makes it easier for the maintainers to quickly release your changes :)

[source-knights]

As mentioned in the encoding issue you fixed for me, I now coded the tsfmt maven plugin. Not sure if I am missing something, but hopefully it will be spot then in this review. Happy to make amendments ,)

I had to disable the new test method for tsconfig based files in my new TypescriptFormatStepTest, cause it is always failing with both, an error about a Legacy "-color" flag that is used and that inputs are missing. I assume the "-color" flag error leads to the inputs missing error message. But I could not figure out why. I see that this color flag is used in the existing base code.

[nedtwigg]

This looks beautiful, a canonical example of "add maven support for X". Thanks very much. I'll make some changes to the docs and take a look at fixing the @Ignored unit test, then merge and release. Might take a few days before I get to it.

[source-knights]

Happy to help if anything comes up. Thx @nedtwigg for the quick response. Stay healthy :)

[nedtwigg]

I made some minor changes:

• changed the default includes from **/*.ts to src/**/*.ts
• compressed the docs

I made a bigger change, but accidentally pushed to origin/master instead of source-knights/master 😭 and have therefore bricked this PR. The problem is that there's still a problem, which I guess I'll have to make a new issue/PR to resolve...

[nedtwigg]

Continued in #553