feat: customize getting started page (#5707)

* feat: add getting-started patch

This modifies the text on the Getting Started page to promote
coder/coder.

* feat: add --disable-getting-started-override

This adds a new CLI flag to code-server called
`--disable-getting-started` which will be used in Code to not use
Coder's custom Getting Started text.

* refactor: conditionally show coder getting started

This modifies the getting started patch changes to work with the new
`--disable-getting-started-override`.

The flag is false by default meaning the Coder getting started is shown.
By passing the flag to code-server, it will not be shown.

* docs: update faq for getting started override

* docs: update getting-started patch description

* fixup!: update patch

* fixup!: unit test

* feat: add more tests

* fixup!: use correct env var in tests

Co-authored-by: repo-ranger[bot] <39074581+repo-ranger[bot]@users.noreply.github.com>

src/node/cli.ts

@@ -51,6 +51,7 @@ export interface UserProvidedCodeArgs {
   "disable-update-check"?: boolean
   "disable-file-downloads"?: boolean
   "disable-workspace-trust"?: boolean
+  "disable-getting-started-override"?: boolean
 }
 
 /**
@@ -170,6 +171,10 @@ export const options: Options<Required<UserProvidedArgs>> = {
     type: "boolean",
     description: "Disable Workspace Trust feature. This switch only affects the current session.",
   },
+  "disable-getting-started-override": {
+    type: "boolean",
+    description: "Disable the coder/coder override in the Help: Getting Started page.",
+  },
   // --enable can be used to enable experimental features. These features
   // provide no guarantees.
   enable: { type: "string[]" },
@@ -563,6 +568,10 @@ export async function setDefaults(cliArgs: UserProvidedArgs, configArgs?: Config
     args["disable-file-downloads"] = true
   }
 
+  if (process.env.CS_DISABLE_GETTING_STARTED_OVERRIDE?.match(/^(1|true)$/)) {
+    args["disable-getting-started-override"] = true
+  }
+
   const usingEnvHashedPassword = !!process.env.HASHED_PASSWORD
   if (process.env.HASHED_PASSWORD) {
     args["hashed-password"] = process.env.HASHED_PASSWORD