docs: condense get started fast section (#504)

* Initial plan

* docs: shorten get started fast section

Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

* docs: add usage to get started fast

Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>

---------

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: Mossaka <5447827+Mossaka@users.noreply.github.com>
Co-authored-by: Jiaxiao (mossaka) Zhou <duibao55328@gmail.com>

Author: Copilot

README.md

@@ -21,16 +21,12 @@ See [Compatibility](docs/compatibility.md) for full details on supported version
 
 ## Get started fast
 
-- **Prerequisite:** Docker is running
-- **Install:**
-  ```bash
-  curl -sSL https://raw.githubusercontent.com/github/gh-aw-firewall/main/install.sh | sudo bash
-  ```
-- **Run your first command:**
-  ```bash
-  sudo awf --allow-domains github.com -- curl https://api.github.com
-  ```
-  The `--` separator passes the command you want to run behind the firewall.
+```bash
+curl -sSL https://raw.githubusercontent.com/github/gh-aw-firewall/main/install.sh | sudo bash
+sudo awf --allow-domains github.com -- curl https://api.github.com
+```
+
+The `--` separator divides firewall options from the command to run.
 
 ### GitHub Copilot CLI in one line