docs(installer): Fix typography and align headers

docs/site/getting-started/installer.md

@@ -61,7 +61,8 @@ sudo umount /dev/sdb1
 
         The `clan flash` utility will erase the disk. Make sure to specify the correct device
 
-    - **SSH-Pubkey Option**:
+    - **SSH-Pubkey Option**
+
         To add an ssh public key into the installer image append the option:
         ```
         --ssh-pubkey <pubkey_path>
@@ -69,19 +70,21 @@ sudo umount /dev/sdb1
         If you do not have an ssh key yet, you can generate one with `ssh-keygen -t ed25519` command.
         This ssh key will be installed into the root user.
 
-    - **Connect to the installer
+    - **Connect to the installer**
 
         On boot, the installer will display on-screen the IP address it received from the network.
         If you need to configure Wi-Fi first, refer to the next section.
         If Multicast-DNS (Avahi) is enabled on your own machine, you can also access the installer using the `flash-installer.local` address.
 
-    - **List Keymaps**:
+    - **List Keymaps**
+
         You can get a list of all keymaps with the following command:
         ```
         clan flash list keymaps
         ```
 
-    - **List Languages**:
+    - **List Languages**
+
         You can get a list of all languages with the following command:
         ```
         clan flash list languages