Custom instructions for features (#1314)

* Custom instructions for github-cli, node, python

* Custom instructions for docker-in-docker, docker-outside-of-docker

Author: chrmarti

src/docker-in-docker/devcontainer-feature.json

@@ -71,7 +71,14 @@
         "vscode": {
             "extensions": [
                 "ms-azuretools.vscode-docker"
-            ]
+            ],
+            "settings": {
+                "github.copilot.chat.codeGeneration.instructions": [
+                    {
+                        "text": "This dev container includes the Docker CLI (`docker`) pre-installed and available on the `PATH` for running and managing containers using a dedicated Docker daemon running inside the dev container."
+                    }
+                ]
+            }
         }
     },
     "mounts": [

src/docker-outside-of-docker/devcontainer-feature.json

@@ -51,7 +51,14 @@
         "vscode": {
             "extensions": [
                 "ms-azuretools.vscode-docker"
-            ]
+            ],
+            "settings": {
+                "github.copilot.chat.codeGeneration.instructions": [
+                    {
+                        "text": "This dev container includes the Docker CLI (`docker`) pre-installed and available on the `PATH` for running and managing containers using the Docker daemon on the host machine."
+                    }
+                ]
+            }
         }
     },
     "mounts": [

src/github-cli/devcontainer-feature.json

@@ -19,6 +19,17 @@
             "default": true
         }
     },
+    "customizations": {
+        "vscode": {
+            "settings": {
+                "github.copilot.chat.codeGeneration.instructions": [
+                    {
+                        "text": "This dev container includes the GitHub CLI (`gh`), which is pre-installed and available on the `PATH`. IMPORTANT: `gh api -f` does not support object values, use multiple `-f` flags with hierarchical keys and string values instead. When using GitHub actions `actions/upload-artifact` or `actions/download-artifact` use v4 or later."
+                    }
+                ]
+            }
+        }
+    },
     "installsAfter": [
         "ghcr.io/devcontainers/features/common-utils",
         "ghcr.io/devcontainers/features/git"

src/node/devcontainer-feature.json

@@ -61,7 +61,14 @@
         "vscode": {
             "extensions": [
                 "dbaeumer.vscode-eslint"
-            ]
+            ],
+            "settings": {
+                "github.copilot.chat.codeGeneration.instructions": [
+                    {
+                        "text": "This dev container includes `node`, `npm` and `eslint` pre-installed and available on the `PATH` for Node.js and JavaScript development."
+                    }
+                ]
+            }
         }
     },
     "containerEnv": {

src/python/devcontainer-feature.json

@@ -77,6 +77,11 @@
         "ms-python.autopep8"
       ],
       "settings": {
+        "github.copilot.chat.codeGeneration.instructions": [
+          {
+            "text": "This dev container includes `python3` and `pip3` pre-installed and available on the `PATH`, along with the Python language extensions for Python development."
+          }
+        ],
         "python.defaultInterpreterPath": "/usr/local/python/current/bin/python",
         "[python]": {
           "editor.defaultFormatter": "ms-python.autopep8"