docs: update ipcam docs

doc/ipcam-streaming.md

@@ -1,10 +1,3 @@
-Let's assume IP cameras stream h264 via rtsp.
-
-To `/etc/fstab`:
-```
-tmpfs /var/ipcamfs tmpfs mode=1755,uid=1000,gid=1000 0 0
-```
-
 For event-based FTP storage:
 ```
 apt install vsftpd
@@ -17,4 +10,40 @@ allow_writeable_chroot=YES
 
 write_enable=YES
 seccomp_sandbox=NO
-```
+```
+
+### HLS
+
+Let's assume IP cameras stream h264 via rtsp.
+
+- Create `/var/ipcamfs` directory.
+
+- Add to `/etc/fstab`:
+  ```
+  tmpfs /var/ipcamfs tmpfs mode=1755,uid=1000,gid=1000,size=350M 0 0
+  ```
+
+  You may want to adjust tmpfs size.
+
+- Run `mount /var/ipcamfs`.
+
+- Copy systemd unit file:
+  ```
+  cp /home/user/homekit/systemd/ipcam_rtsp2hls@.service /etc/systemd/system
+  ```
+
+- Create configuration directory:
+  ```
+  mkdir /etc/ipcam_rtsp2hls.conf.d
+  ```
+
+- Then for each `camname`:
+  - create `/etc/ipcam_rtsp2hls.conf.d/camname.conf` with following content:
+    ```
+    USER=suer
+    PASSWORD=password
+    IP=192.168.1.2
+    PORT=554
+    ARGS=
+    ```
+  - run `systemctl enable ipcam_rtsp2hls@camname` and `systemctl start ipcam_rtsp2hls@camname`