feature #1369 Create devcontainer.json (shyim)

This PR was merged into the main branch.

Discussion
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Create devcontainer.json

Adds an example how to setup it on [GitHub Codespaces](https://github.com/features/codespaces)

Commits
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1db3c9b Create devcontainer.json

Author: javiereguiluz

.devcontainer/devcontainer.json

@@ -0,0 +1,20 @@
+{
+  "image": "mcr.microsoft.com/devcontainers/base:ubuntu",
+  "features": {
+    "ghcr.io/shyim/devcontainers-features/symfony-cli:0": {},
+    "ghcr.io/shyim/devcontainers-features/php:0": {
+      "version": "8.1"
+    },
+    "ghcr.io/devcontainers/features/node:1": {
+      "version": "lts"
+    }
+  },
+  "updateContentCommand": {
+    "composer install": ["composer", "install"],
+    "yarn": ["yarn"]
+  },
+  "postAttachCommand": {
+    "server": "symfony server:start",
+    "yarn": ["yarn", "watch"]
+  }
+}