Update docs and comments

lib/syntax_suggest/capture_code_context.rb

@@ -15,7 +15,7 @@ module SyntaxSuggest
   #
   # 1. Sanitize/format input source
   # 2. Search for invalid blocks
-  # 3. Format invalid blocks into something meaninful
+  # 3. Format invalid blocks into something meaningful
   #
   # This class handles the third part.
   #

lib/syntax_suggest/clean_document.rb

@@ -10,7 +10,7 @@ module SyntaxSuggest
   #
   # 1. Sanitize/format input source
   # 2. Search for invalid blocks
-  # 3. Format invalid blocks into something meaninful
+  # 3. Format invalid blocks into something meaningful
   #
   # This class handles the first part.
   #

lib/syntax_suggest/code_frontier.rb

@@ -8,7 +8,7 @@ module SyntaxSuggest
   #
   # 1. Sanitize/format input source
   # 2. Search for invalid blocks
-  # 3. Format invalid blocks into something meaninful
+  # 3. Format invalid blocks into something meaningful
   #
   # The Code frontier is a critical part of the second step
   #

lib/syntax_suggest/mini_stringio.rb

@@ -1,8 +1,14 @@
+# frozen_string_literal: true
+
 module SyntaxSuggest
   # Mini String IO [Private]
   #
   # Acts like a StringIO with reduced API, but without having to require that
   # class.
+  #
+  # The original codebase emitted directly to $stderr, but now SyntaxError#detailed_message
+  # needs a string output. To accomplish that we kept the original print infrastructure in place and
+  # added this class to accumulate the print output into a string.
   class MiniStringIO
     EMPTY_ARG = Object.new