Add syntax highlighting to Yarn lockfiles (#4761)

* Adds proper highlighting for Yarn's lockfile

* Adds samples

* Moves the Yarn 2 lockfile to filenames

* Optimizes the yarn.lock content

lib/linguist/languages.yml

@@ -6130,6 +6130,7 @@ YAML:
   - ".clang-tidy"
   - ".gemrc"
   - glide.lock
+  - yarn.lock
   ace_mode: yaml
   codemirror_mode: yaml
   codemirror_mime_type: text/x-yaml

samples/YAML/filenames/yarn.lock

@@ -0,0 +1,30 @@
+# This file is generated by running "yarn install" inside your project.
+# Manual changes might be lost - proceed with caution!
+
+__metadata:
+  version: 4
+
+"@algolia/cache-browser-local-storage@npm:4.0.1":
+  version: 4.0.1
+  resolution: "@algolia/cache-browser-local-storage@npm:4.0.1"
+  dependencies:
+    "@algolia/cache-common": 4.0.1
+  checksum: 2/bc61ab01a2723fe319eb41271f196b208f04d52db75526a87dd5189824be2b8dc1c7f0bdc93d958eb80192c20ba467709a87a227d8bc29f69549e28a5e8b0c66
+  languageName: node
+  linkType: hard
+
+"@algolia/cache-common@npm:4.0.1":
+  version: 4.0.1
+  resolution: "@algolia/cache-common@npm:4.0.1"
+  checksum: 2/4016b1e91e91eb1cd11d452c807579d679daee3ddb605e083bd3f1ffc2426af4bc5b831316c67cf4d10c8d9e042e70b835fbcc6e14be59556f3b3d2f113c9774
+  languageName: node
+  linkType: hard
+
+"@algolia/cache-in-memory@npm:4.0.1":
+  version: 4.0.1
+  resolution: "@algolia/cache-in-memory@npm:4.0.1"
+  dependencies:
+    "@algolia/cache-common": 4.0.1
+  checksum: 2/04118bbf8e4d491b32fc8575a9f1b5b3393782c0237f93486d3408600865da56902a1c0c077fc9844127789927bc44192032a79cac442e74735853f85e4fef60
+  languageName: node
+  linkType: hard