Update, clean up VS Code dev container definition (#1863)

* Update and clean up

- Use current hyperlinks.
- Remove redundant explanation and refer to official docs, now dev
containers have gained maturity.

* Update and clean up

- Spell project name more correctly.
- Normalize `Dockerfile` path.
- Remove deprecated setting, leave it to the defaults.
- Add the EditorConfig extension, since the project uses it already and
the functionality is quite critical for contribution.

.devcontainer/README.md

@@ -1,10 +1,5 @@
-# Devcontainer
+# Visual Studio Code dev container configuration
 
-This file specifies to vscode how to run the container
+This file specifies to Visual Studio Code how to run a [dev container](https://code.visualstudio.com/docs/remote/containers).
 
-For format details, see [documentation](https://aka.ms/vscode-remote/devcontainer.json) or this file's [README](https://github.com/microsoft/vscode-dev-containers/tree/v0.123.0/containers/docker-existing-dockerfile)
-
-context: Sets the run context to one level up instead of the .devcontainer folder.
-dockerFile: Update the 'dockerFile' property if you aren't using the standard 'Dockerfile' filename.
-settings: Set _default_ container specific settings.json values on container create.
-extensions: Add the IDs of extensions you want installed when the container is created.
+For format details, see [documentation](https://code.visualstudio.com/docs/remote/devcontainerjson-reference).

.devcontainer/devcontainer.json

@@ -1,12 +1,10 @@
 {
-  "name": "SUPER-LINTER",
+  "name": "Super-Linter",
   "context": "..",
-  "dockerFile": "..//Dockerfile",
-  "settings": {
-    "terminal.integrated.shell.linux": "/bin/bash"
-  },
+  "dockerFile": "../Dockerfile",
   "extensions": [
     "github.vscode-pull-request-github",
-    "rogalmic.bash-debug"
+    "rogalmic.bash-debug",
+    "EditorConfig.EditorConfig"
   ]
 }