Docs: landing page revamp (#8885)

* Docs: refresh landing page

* Docs: add landing page companion pages

* Docs: drop legacy Jekyll assets

* Docs: remove legacy terminal css test

* Docs: restore terminal css assets

* Docs: remove terminal css assets

docs/start/quickstart.md

@@ -0,0 +1,81 @@
+---
+summary: "Install OpenClaw, onboard the Gateway, and pair your first channel."
+read_when:
+  - You want the fastest path from install to a working Gateway
+title: "Quick start"
+---
+
+<Note>
+OpenClaw requires Node 22 or newer.
+</Note>
+
+## Install
+
+<Tabs>
+  <Tab title="npm">
+    ```bash
+    npm install -g openclaw@latest
+    ```
+  </Tab>
+  <Tab title="pnpm">
+    ```bash
+    pnpm add -g openclaw@latest
+    ```
+  </Tab>
+</Tabs>
+
+## Onboard and run the Gateway
+
+<Steps>
+  <Step title="Onboard and install the service">
+    ```bash
+    openclaw onboard --install-daemon
+    ```
+  </Step>
+  <Step title="Pair WhatsApp">
+    ```bash
+    openclaw channels login
+    ```
+  </Step>
+  <Step title="Start the Gateway">
+    ```bash
+    openclaw gateway --port 18789
+    ```
+  </Step>
+</Steps>
+
+After onboarding, the Gateway runs via the user service. You can still run it manually with `openclaw gateway`.
+
+<Info>
+Switching between npm and git installs later is easy. Install the other flavor and run
+`openclaw doctor` to update the gateway service entrypoint.
+</Info>
+
+## From source (development)
+
+```bash
+git clone https://github.com/openclaw/openclaw.git
+cd openclaw
+pnpm install
+pnpm ui:build # auto-installs UI deps on first run
+pnpm build
+openclaw onboard --install-daemon
+```
+
+If you do not have a global install yet, run onboarding via `pnpm openclaw ...` from the repo.
+
+## Multi instance quickstart (optional)
+
+```bash
+OPENCLAW_CONFIG_PATH=~/.openclaw/a.json \
+OPENCLAW_STATE_DIR=~/.openclaw-a \
+openclaw gateway --port 19001
+```
+
+## Send a test message
+
+Requires a running Gateway.
+
+```bash
+openclaw message send --target +15555550123 --message "Hello from OpenClaw"
+```