Removing references of CSON from the contribution guide

Author: Polgár Márton

CONTRIBUTING.md

@@ -56,10 +56,7 @@ Because of this, a priority system is the best way to categorize any issues.
 ### Atom Grammars
 
 * Atom uses a TextMate type grammar. While TextMate uses plist's(XMLish),
-  Atom stores them in [CSON][CSON] format.
-* In CSON, indentation matters. Don't forget this!
-* In CSON the only characters that need to be escaped inside a single quoted
-  string are single quotes(`'`), backslashes(`\`) and control codes.
+  Atom stores them in JSON format.
 * The code that Atom uses to actually process the grammars is called
   [first-mate][first-mate].
 * Lines above and below each other that are on the same indentation level
@@ -82,8 +79,8 @@ Because of this, a priority system is the best way to categorize any issues.
   TextMate style grammars (Sublime, Atom, TextMate).
 * If you want use a hex codepoint instead of typing the symbol in, please use
   `\\x{20}` (Unescaped form: `\x{20}`).
-  This will use the Regex engine for this instead of using the JSON/CSON method
-  of noting unicode codepoints (e.g. `\u20` which can be used in CSON/JSON).
+  This will use the Regex engine for this instead of using the JSON method
+  of noting unicode codepoints (e.g. `\u20` which can be used in JSON).
 * Specify Unicode properties like this: `\\p{Alpha}`(`\p{Alpha}` in unescaped
   form). See the cheatsheet linked below for all the ones that are guaranteed
   to work.
@@ -93,18 +90,16 @@ Because of this, a priority system is the best way to categorize any issues.
 
 * A helpful site to try out Ruby regex is [Rubular][Rubular], although it only
   assumes `/…/` regex syntax so you must escape forward slashes. You do not
-  need to escape forward slashes in the CSON file.
+  need to escape forward slashes in the JSON file.
 * [Regex101](regex101.com) is more graphical and nicer but make
   sure to test out the regex on [Rubular][Rubular] once you have it assembled!
 
 ## TextMate Grammar Documentation
 Reading the [documentation][textmate] for TextMate grammars is informative but
 leaves some things unanswered. In this section I will go over the basics.
 
-The CSON file at the top has the patterns which are matched, in order from top
-to bottom. As I said in the CSON section, indentation in CSON is significant,
-and anything not bracketed above and below each other on the same level of
-indentation does not retain order of the elements of the list.
+The JSON file at the top has the patterns which are matched, in order from top
+to bottom.
 
 ### Single line/simple matching
 The bottom of the file has named sections which can be 'included' into other
@@ -131,11 +126,11 @@ on top of the previous ones. You list the subrules in the Patterns section
 of the rule you are working on.
 
 ### Show me the source already!
-The majority of the grammar is included in `grammars/raku.cson`.
+The majority of the grammar is included in `grammars/raku.tmLanguage.json`.
 The `q[]`, `qq[]`, `Q[]`, `"…"` etc. quoting is generated by
 `dev/q-qq-Q-template.raku`. Multi-line comments are also generated. The q
-types of quoting are added to `raku.quoting.cson`. The standard quotation
-marks are added to `raku.cson`.
+types of quoting are added to `raku.quoting.tmLanguage.json`. The standard quotation
+marks are added to `raku.tmLanguage.json`.
 
 Once you have edited `q-qq-Q-template.raku`, run `dev/replace.sh` which uses
 awk to do the replacement. Eventually it will be nice if we had a purely Raku
@@ -158,7 +153,6 @@ error out when you run `apm test` yourself).
 
 
 
-[CSON]: https://github.com/bevry/cson
 [Rubular]: http://rubular.com/
 [Oniguruma]: https://en.wikipedia.org/wiki/Oniguruma
 [Oniguruma-RE]: https://github.com/kkos/oniguruma/blob/master/doc/RE