Add --js as an alias for --replacement-js #715

Today

--replacement-js (-j) treats the replacement as javascript. --js is an unknown argument.

Change

--js does the same as --replacement-js.

> rexreplace foo '2+2' my.file --js

Good to know

• This was made on the v8.0 and v8/autofix branches, which are not merged. v8/autofix has a CLI test for it.
• The help text and the table of options in the README must show the new name.

Reference

This was made before, on a branch that is not merged. Look at it to see how it was done. It can not be copied as it is, as it is written for older code.

• src/cli.ts lines 258-259 on v8.0: replacementJs with the alias js.
• test/cli/run.sh line 364 on v8/autofix: a CLI test.