Fix doc sigil with paren

Fixes #477

Author: jbodah

syntax/elixir.vim

@@ -125,15 +125,15 @@ else
  syn region elixirDocTest start="^\s*\%(iex\|\.\.\.\)\%((\d*)\)\?>\s" end="^\s*$" contained
 endif
 
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\s\+\)\@<=\~[Ss]\z(/\|\"\|'\||\)" end="\z1" skip="\\\\\|\\\z1" contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\s\+\)\@<=\~[Ss]{" end="}" skip="\\\\\|\\}" contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\s\+\)\@<=\~[Ss]<" end=">" skip="\\\\\|\\>" contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\s\+\)\@<=\~[Ss]\[" end="\]" skip="\\\\\|\\\]" contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\s\+\)\@<=\~[Ss](" end=")" skip="\\\\\|\\)" contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocStringDelimiter start=+\%(@\w*doc\s\+\)\@<=\z("\)+ end=+\z1+ skip=+\\\\\|\\\z1+ contains=@elixirDocStringContained keepend
-syn region elixirDocString matchgroup=elixirDocStringDelimiter start=+\%(@\w*doc\s\+\)\@<=\z("""\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start=+\%(@\w*doc\s\+\)\@<=\~[Ss]\z('''\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
-syn region elixirDocString matchgroup=elixirDocSigilDelimiter start=+\%(@\w*doc\s\+\)\@<=\~[Ss]\z("""\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]\z(/\|\"\|'\||\)" end="\z1" skip="\\\\\|\\\z1" contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]{" end="}" skip="\\\\\|\\}" contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]<" end=">" skip="\\\\\|\\>" contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]\[" end="\]" skip="\\\\\|\\\]" contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start="\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss](" end=")" skip="\\\\\|\\)" contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocStringDelimiter start=+\%(@\w*doc\(\s\|(\)\+\)\@<=\z("\)+ end=+\z1+ skip=+\\\\\|\\\z1+ contains=@elixirDocStringContained keepend
+syn region elixirDocString matchgroup=elixirDocStringDelimiter start=+\%(@\w*doc\(\s\|(\)\+\)\@<=\z("""\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start=+\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]\z('''\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
+syn region elixirDocString matchgroup=elixirDocSigilDelimiter start=+\%(@\w*doc\(\s\|(\)\+\)\@<=\~[Ss]\z("""\)+ end=+^\s*\z1+ contains=@elixirDocStringContained fold keepend
 
 " Defines
 syn match elixirDefine '\<def\>\(:\)\@!' nextgroup=elixirFunctionDeclaration skipwhite skipnl