feat(developer): Add linting of project file layout and file names

In keymanapp/keyboards#3414, @DavidLRowe wrote:

As you are checking on folder/file names and structure, could you provide a "lint" report for the reviewers (and indeed for the keyboard authors):

- no .kvks file found
- misplaced readme.htm file: release/x/xyz/readme.htm
- missing folder release/x/xyz/help
- extra folder release/x/xyz/build
- extra file release/x/xyz/source/xyz.kmx