Add dev container configuration for repo (microsoft#3440)

This should help opening PR in codespaces as well as helping new
contributors

Author: timotheeguerin

.devcontainer/Dockerfile

@@ -0,0 +1,4 @@
+FROM mcr.microsoft.com/devcontainers/javascript-node:20
+
+RUN corepack enable pnpm && \
+  echo 'alias pnpm="corepack pnpm"' >> /home/node/.bash_aliases

.devcontainer/devcontainer.json

@@ -0,0 +1,18 @@
+{
+  "name": "Standard",
+  "build": {
+    "dockerfile": "Dockerfile"
+  },
+  "customizations": {
+    // Configure properties specific to VS Code.
+    "vscode": {
+      // Add the IDs of extensions you want installed when the container is created.
+      "extensions": [
+        "dbaeumer.vscode-eslint",
+        "esbenp.prettier-vscode",
+        "streetsidesoftware.code-spell-checker",
+        "vitest.explorer"
+      ]
+    }
+  }
+}

.npmrc

@@ -1 +1,2 @@
 auto-install-peers=true
+package-manager-strict=false

cspell.yaml

@@ -26,11 +26,13 @@ words:
   - createsorreplacesresource
   - createsorupdatesresource
   - CRUDL
+  - dbaeumer
   - debouncer
   - devdiv
   - dogfood
   - eastus
   - ecmarkup
+  - esbenp
   - esbuild
   - espt
   - ESRP

docker/Dockerfile

@@ -8,7 +8,7 @@ COPY . /app
 
 WORKDIR /app
 ENV TYPESPEC_SKIP_VS_BUILD=1
-RUN npm install -g pnpm@8.13.1
+RUN corepack enable && corepack prepare
 RUN pnpm install --frozen-lockfile
 RUN pnpm --filter "@typespec/compiler..." run build
 

eng/tsp-core/pipelines/templates/install.yml

@@ -27,7 +27,7 @@ steps:
 
   - script: |
       corepack enable
-      corepack prepare pnpm@latest-8 --activate
+      corepack prepare pnpm --activate
     displayName: Install pnpm
   - script: pnpm config set store-dir ${{ parameters.pnpmStorePath }}
     displayName: Setup pnpm cache dir