Improve indentation of tags and comments.

Tags on features are indented at 0.

Other tags are indented at the same level as Scenario headers (one
shiftwidth). This matches all the examples I have read.

Comments above a feature are indented at 0.

Comments after a blank line are indented at the same level as Scenario
headers (one shiftwidth).

All other comments preserve the indent of the line before them.

indent/cucumber.vim

@@ -29,32 +29,42 @@ function! GetCucumberIndent()
   let csyn = s:syn(v:lnum)
   let nsyn = s:syn(nextnonblank(v:lnum+1))
   if csyn ==# 'cucumberFeature' || cline =~# '^\s*Feature:'
+    " feature heading
     return 0
   elseif csyn ==# 'cucumberExamples' || cline =~# '^\s*\%(Examples\|Scenarios\):'
+    " examples heading
     return 2 * &sw
   elseif csyn =~# '^cucumber\%(Background\|Scenario\|ScenarioOutline\)$' || cline =~# '^\s*\%(Background\|Scenario\|Scenario Outline\):'
+    " background, scenario or outline heading
     return &sw
   elseif syn ==# 'cucumberFeature' || line =~# '^\s*Feature:'
+    " line after feature heading
     return &sw
   elseif syn ==# 'cucumberExamples' || line =~# '^\s*\%(Examples\|Scenarios\):'
+    " line after examples heading
     return 3 * &sw
   elseif syn =~# '^cucumber\%(Background\|Scenario\|ScenarioOutline\)$' || line =~# '^\s*\%(Background\|Scenario\|Scenario Outline\):'
+    " line after background, scenario or outline heading
     return 2 * &sw
-  elseif cline =~# '^\s*@' && (nsyn == 'cucumberFeature' || nline =~# '^\s*Feature:' || indent(prevnonblank(v:lnum-1)) <= 0)
+  elseif cline =~# '^\s*[@#]' && (nsyn == 'cucumberFeature' || nline =~# '^\s*Feature:' || indent(prevnonblank(v:lnum-1)) <= 0)
+    " tag or comment before a feature heading
     return 0
-  elseif line =~# '^\s*@'
+  elseif cline =~# '^\s*@'
+    " other tags
     return &sw
-  elseif cline =~# '^\s*|' && line =~# '^\s*|'
+  elseif cline =~# '^\s*[#|]' && line =~# '^\s*|'
+    " mid-table
+    " preserve indent
     return indent(prevnonblank(v:lnum-1))
-  elseif cline =~# '^\s*|' && line =~# '^\s*[^|#]'
+  elseif cline =~# '^\s*|' && line =~# '^\s*[^|]'
+    " first line of a table, relative indent
     return indent(prevnonblank(v:lnum-1)) + &sw
-  elseif cline =~# '^\s*[^|# \t]' && line =~# '^\s*|'
+  elseif cline =~# '^\s*[^|]' && line =~# '^\s*|'
+    " line after a table, relative unindent
     return indent(prevnonblank(v:lnum-1)) - &sw
-  elseif cline =~# '^\s*$' && line =~# '^\s*|'
-    let in = indent(prevnonblank(v:lnum-1))
-    return in == indent(v:lnum) ? in : in - &sw
-  elseif cline =~# '^\s*#' && getline(v:lnum-1) =~ '^\s*$' && getline(v:lnum+1) =~# '\S'
-    return indent(getline(v:lnum+1))
+  elseif cline =~# '^\s*#' && getline(v:lnum-1) =~ '^\s*$' && (nsyn =~# '^cucumber\%(Background\|Scenario\|ScenarioOutline\)$' || nline =~# '^\s*\%(Background\|Scenario\|Scenario Outline\):')
+    " comments on scenarios
+    return &sw
   endif
   return indent(prevnonblank(v:lnum-1))
 endfunction