chore: remove unused /docs code (#54334)

.devcontainer/docs/Dockerfile

@@ -1,6 +0,0 @@
-FROM node:20-alpine
-
-# Install git
-RUN apk add --no-cache git
-
-RUN npm install -g docsify-cli prettier eslint

.devcontainer/docs/devcontainer.json

@@ -1,24 +0,0 @@
-{
-  "context": "../..",
-  "customizations": {
-    "codespaces": {
-      "openFiles": ["docs/how-to-work-on-the-docs-theme.md"]
-    },
-    "vscode": {
-      "extensions": [
-        "dbaeumer.vscode-eslint",
-        "esbenp.prettier-vscode",
-        "freeCodeCamp.freecodecamp-dark-vscode-theme"
-      ]
-    }
-  },
-  "dockerFile": "Dockerfile",
-  "forwardPorts": [3400],
-  "portsAttributes": {
-    "3400": {
-      "label": "Docs",
-      "onAutoForward": "openPreview"
-    }
-  },
-  "postAttachCommand": "npm run docs:serve"
-}