Emacs UI LSP configuration for Clojure LSP

[practicalli-johnny]

• Provide a minimal setup for Clojure LSP / Emacs LSP UI in the practicalli/spacemacs.d repository
• Add quick start section on https://practical.li/spacemacs/install-spacemacs/clojure-lsp/
• Explain the Practicalli configuration for LSP with CIDER
• Describe additional configuration that may be desirable and link to the canonical reference pages

Canonical pages:
https://emacs-lsp.github.io/lsp-mode/tutorials/clojure-guide/
https://emacs-lsp.github.io/lsp-mode/tutorials/how-to-turn-off/