install prettier to rush project

Basically same as document here

But this not using pretty-quick.

It's very like pretty-quick but for rush project only.

usage:

pnpx @build-script/rush-pretty --install

options:

• rush prettier --changed or rush prettier: format changed files.
• rush prettier --staged: same as pretty-quick.
• rush prettier --all: format all files in git repo, no matter changed or not.

special note:

1. You must use git repo. This script will not work without git.
2. gitignore and prettier ignore always merge (but not write to disk), you do not need copy gitignore content to prettierignore.
3. --staged format files in working tree, which has staged copy. Does not really care the file in the stage. This is also what pretty-quick do.
4. Anything in newly added folder will not format before git add. Even with --all flag.