* add readme.md for rtx
* add rtx plugin
* update install info
* remove redundant slashes

Closes #11143
Closes #8779

Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

BREAKING CHANGE: `gt` alias clashes with Graphite CLI
(https://graphite.dev). See https://github.com/ohmyzsh/ohmyzsh/pull/11910#issuecomment-1736340910

Co-authored-by: hasecilu <hasecilu@protonmail.com>
Co-authored-by: Rik <gitaarik@posteo.net>
Co-authored-by: Carlo Sala <carlosalag@protonmail.com>

Co-authored-by: Gabriel Akinyosoye <gabrielfemi799@gmail.com>

Co-authored-by: Marcus Müller <marcus_ohmyzsh@baseband.digital>

`vc link` is not needed, as we already have `VERCEL_PROJECT_ID`
defined as an env variable. Currently the `vc link` only creates
a second empty project with the name `installer` as seen in logs:

  Linked to ohmyzsh/installer (created .vercel and added it to .gitignore)
  Vercel CLI 32.2.4

Fixes #11888

Co-authored-by: Matt Cable <github@curiousstranger.org>

Closes #11879

Closes #11472

Closes #11876

Closes #7489
Closes #9721

Fixes #11686

Co-authored-by: K. Akatsuki <thevortexspirit@gmail.com>