Remove help plugin stuff

IMO this just doesn't belong here, it ought to be a separate plugin or
perhaps in Derek's personal ~/.vim/after/plugin :-) It doesn't even
appear to apply to the current help file format for this project.

I also didn't understand the change in 65e924f from derekwyatt#6 that put the
`JustifyCurrentLine` mapping in `ftplugin/scala.vim` -- the function is
for help files yet it was mapped buffer-local in Scala files. Goodbye.

Also while I was looking at mappings, put the current ones in Vim doc.

Author: ches

after/plugin/help.vim

@@ -1,6 +1,12 @@
-let b:current_syntax = ''
-unlet b:current_syntax
+" Extends standard help syntax with highlighting of Scala code.
+"
+" Place code between !sc! and !/sc! delimiters. These will be hidden if Vim is
+" built with conceal support.
+
+unlet! b:current_syntax
+
 syntax include @ScalaCode syntax/scala.vim
+
 if has('conceal')
   syntax region rgnScala matchgroup=Ignore concealends start='!sc!' end='!/sc!' contains=@ScalaCode
 else

after/syntax/help.vim

@@ -1,9 +1,11 @@
 *scala.txt* Syntax highlighting and helper functions for the Scala language.
 
+==============================================================================
 INTRODUCTION                                    *scala*
 
 Syntax highlighting and helper functions for the scala language.
 
+==============================================================================
 COMMANDS                                        *scala-commands*
 
                                                 *:SortScalaImports*
@@ -41,4 +43,40 @@ COMMANDS                                        *scala-commands*
                           g:scala_first_party_namespaces=
                              \ '\(controllers\|views\|models\)'
 
+==============================================================================
+MAPPINGS                                        *scala-mappings*
 
+Currently the only mappings defined are for FuzzyFinder users--these will
+only be enabled if FuzzyFinder is detected.
+
+                                                *scala-leader-fs*
+<Leader>fs              "Find src". Primes |:FufFile| with `src/main/scala`,
+                        and goes deeper still if only a single directory
+                        exists below that. Helpful for package namespacing
+                        like `src/main/scala/com/myorg`.
+
+                                                *scala-leader-ft*
+<Leader>ft              "Find test". Like |scala-leader-fs|, but with
+                        `src/test/scala`.
+
+                                                *scala-leader-fr*
+<Leader>fr              "Find from root". For the rarer cases when you want to
+                        start FuzzyFinder at project root (parent of `src/`).
+
+Disabling Mappings~
+
+If you wish to disable the default key mappings, write the following line in
+your ~/.vimrc: >
+
+    let g:scala_use_default_keymappings = 0
+
+==============================================================================
+CREDITS                                          *scala-credits*
+
+Developed by Derek Wyatt, building on initial work by Stefan Matthias Aust.
+Distributed under the Apache 2 license.
+
+Project's home and Git repository: https://github.com/derekwyatt/vim-scala
+
+------------------------------------------------------------------------------
+ vim:tw=78:ts=8:ft=help:norl:

doc/scala.txt

@@ -130,12 +130,6 @@ if globpath(&rtp, 'plugin/fuf.vim') != ''
     endif
 endif
 
-" If you want to disable the default key mappings, write the following line in
-" your ~/.vimrc
-"     let g:scala_use_default_keymappings = 0
-if get(g:, 'scala_use_default_keymappings', 1)
-    nnoremap <buffer> <Leader>jt :call JustifyCurrentLine()<cr>
-endif
 
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