Remove references to Lightshow (github-linguist#5845)

.github/PULL_REQUEST_TEMPLATE.md

@@ -27,8 +27,7 @@
     - Sample source(s):
       - [URL to each sample source, if applicable]
     - Sample license(s):
-  <!-- Update the Lightshow URLs below to show the grammar in action if you included one. -->
-  - [ ] I have included a syntax highlighting grammar: https://github-lightshow.herokuapp.com/
+  - [ ] I have included a syntax highlighting grammar: [URL to grammar repo]
   - [ ] I have updated the heuristics to distinguish my language from others using the same extension.
 
 - [ ] **I am fixing a misclassified language**
@@ -39,9 +38,8 @@
   - [ ] I have included a change to the heuristics to distinguish my language from others using the same extension.
 
 - [ ] **I am changing the source of a syntax highlighting grammar**
-  <!-- Update the Lightshow URLs below to show the new and old grammars in action. -->
-  - Old: https://github-lightshow.herokuapp.com/
-  - New: https://github-lightshow.herokuapp.com/
+  - Old: [URL to grammar repo]
+  - New: [URL to grammar repo]
 
 - [ ] **I am updating a grammar submodule**
   <!-- That's not necessary, grammar submodules are updated automatically with each new release. -->
@@ -54,4 +52,4 @@
   <!-- Please ensure you have gathered agreement from the wider language community _before_ opening this PR -->
   - [ ] I have obtained agreement from the wider language community on this color change.
     - [URL to public discussion]
-    - [Optional: URL to official branding guidelines for the language]
+    - [Optional: URL to official branding guidelines for the language]

CONTRIBUTING.md

@@ -142,7 +142,7 @@ You can also try to fix the bug yourself and submit a pull-request.
 [TextMate's documentation](https://manual.macromates.com/en/language_grammars) offers a good introduction on how to work with TextMate-compatible grammars.
 Note that Linguist uses [PCRE](https://www.pcre.org/) regular expressions, while TextMate uses [Oniguruma](https://github.com/kkos/oniguruma).
 Although they are mostly compatible there might be some differences in syntax and semantics between the two.
-You can test grammars using [Lightshow](https://github-lightshow.herokuapp.com).
+Linguist's grammar compiler will highlight any problems when the grammar is updated.
 
 Once the bug has been fixed upstream, we'll pick it up for GitHub in the next release of Linguist.
 

docs/releasing.md

@@ -33,7 +33,6 @@ This is the procedure for making a new release of Linguist. The entire process n
 17. Update and deploy the following repositories to use the new gem in production:
     - `github/github` - label for backporting to the latest version of GitHub Enterprise Server only.
     - `github/treelights` - this only needs the Linguist version updated to pull the compiled grammars from the Linguist release. Label for backporting to the latest version of GitHub Enterprise Server only.
-    - `github/lightshow`
 
     Note: syntax highlighting changes won't take effect until the updated `github/treelights` repo has been deployed.