[docs] lsp-gitpod provides spacemacs config

[yyoncho]

This is just a heads up for spacemacs maintainers. As part of emacs-lsp organization, we have created lsp-gitpod project which ships with preconfigured spacemacs config (in addition it has language servers, natively compiled packages, ripgrep, vterm, etc)

You can try it using this link(make sure the popups are enabled).

https://gitpod.io/#ORG=emacs-lsp,PROJECT=demo-projects,PROFILE=spacemacs/https://github.com/emacs-lsp/lsp-gitpod

Link to the project: https://github.com/emacs-lsp/lsp-gitpod

The project might be useful for spacemacs devs to achieve reproducible env.