Implement Lua ALE setup & overhaul documentation

1. Add ale.setup and ale.setup.buffer for pure Lua configuration.
2. Update many global settings to use Booleans instead of numbers to
   make types easiert to work with in Lua.
3. Radically reformat documentation and fix errors to make
   documentation more usable for Neovim users.

doc/ale-clojure.txt

@@ -9,13 +9,20 @@ A minimal and opinionated linter for code that sparks joy.
 
 https://github.com/borkdude/clj-kondo
 
-g:ale_clojure_clj_kondo_options               *g:ale_clojure_clj_kondo_options*
+
+-------------------------------------------------------------------------------
+Options
+                                        *ale-options.clojure_clj_kondo_options*
+                                              *g:ale_clojure_clj_kondo_options*
                                               *b:ale_clojure_clj_kondo_options*
+clojure_clj_kondo_options
+g:ale_clojure_clj_kondo_options
   Type: |String|
   Default: `'--cache'`
 
   This variable can be changed to modify options passed to clj-kondo.
 
+
 ===============================================================================
 cljfmt                                                     *ale-clojure-cljfmt*
 
@@ -43,6 +50,6 @@ directory.
 
 see https://github.com/candid82/joker#linter-mode for more information.
 
+
 ===============================================================================
   vim:tw=78:ts=2:sts=2:sw=2:ft=help:norl:
-