tree-sitter: 1.18.2 -> 0.19.3

Update the grammars and add `allGrammars` derivation.
`nix-build "<nixpkgs>" -A tree-sitter.allGrammars` will create a
derivation with symlinks to all the grammars

pkgs/development/tools/parsing/tree-sitter/grammars/tree-sitter-css.json

@@ -1,9 +1,9 @@
 {
   "url": "https://github.com/tree-sitter/tree-sitter-css",
-  "rev": "e882c98b5e62d864f7f9e4d855b19b6050c897a8",
-  "date": "2021-02-12T10:45:27-08:00",
-  "path": "/nix/store/g368rqak07i91ddma16pkccp63y2s5yv-tree-sitter-css",
-  "sha256": "0firlbl81vxnw5dp31inabizjhqc37rnbvwf05668qpfjl9gc03z",
+  "rev": "94e10230939e702b4fa3fa2cb5c3bc7173b95d07",
+  "date": "2021-03-04T15:25:23-08:00",
+  "path": "/nix/store/0q3y4zhphdcc54qijbx2pdp8li9idk64-tree-sitter-css",
+  "sha256": "0y90nsfbh13mf33yahbk7zklbv7124rpm0v19qydz6nv1f9hpywd",
   "fetchSubmodules": false,
   "deepClone": false,
   "leaveDotGit": false