Include tmlanguage computed file in repo as we'll need it for github linguist (#2872)

To register a tm language on github linguist we need to publish our
grammar.
Instructions
https://github.com/github-linguist/linguist/blob/master/CONTRIBUTING.md#adding-a-language

.chronus/changes/tmlanguage-published-2024-1-9-1-17-15.md

@@ -0,0 +1,8 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: internal
+packages:
+  - "@typespec/compiler"
+---
+
+Include tmlanguage computed file in repo as we'll need it for github linguist

.prettierignore

@@ -58,3 +58,6 @@ eng/feeds/
 # Skip formatting tsp files
 
 *.noformat.tsp
+
+# Tm Grammars generated files
+grammars/

cspell.yaml

@@ -107,6 +107,7 @@ ignorePaths:
   - "**/.docusaurus/**"
   - "**/CHANGELOG.md"
   - "**/coverage/**"
+  - "grammars/**"
   - packages/website/build/**
   - common/scripts/*
   - "**/ThirdPartyNotices.txt"

packages/compiler/src/server/tmlanguage.ts

@@ -903,6 +903,11 @@ export async function main() {
   const plist = await tm.emitPList(grammar, {
     errorSourceFilePath: resolve("./src/tmlanguage.ts"),
   });
+  const json = await tm.emitJSON(grammar, {
+    errorSourceFilePath: resolve("./src/tmlanguage.ts"),
+  });
   await mkdir("./dist", { recursive: true });
   await writeFile("./dist/typespec.tmLanguage", plist);
+  await mkdir("../../grammars", { recursive: true });
+  await writeFile("../../grammars/typespec.json", json);
 }