add using details

Author: proditis

README.md

@@ -1,18 +1,33 @@
 # Patch OpenBSD bsd.rd with auto_install.conf & rc.firsttime
 
+This is a very simple script that is used to create custom installation cd's and bsd.rd images for OpenBSD to be used with online provides (such as Vultr) to deploy fully configured instances.
+
 The script does the following:
 * Downloads a bsd.rd image from an openbsd mirror
 * Extracts the filesystem portion of the ramdisk
 * Mount the filesystem
 * Patch the filesystem with auto_install
 * Put the filesystem back into bsd.rd
 * Create a `siteXX.tgz` with `rc.firsttime`
-* Create a bootable cd with the modified `bsd.rd` and `siteXX.tgz`
+* Create a bootable ISO with the modified `bsd.rd` and `siteXX.tgz`
 
 In order to preserve size the auto install configuration uses the 1st http
-mirror and then uses the siteXX.tgz from the created CD. This way our CD and
+mirror and then uses the `siteXX.tgz` from the created CD. This way our CD and
 `bsd.rd` are almost the same size.
 
+NOTE: The script is really at its infantry and there is no error checking implemented currently.
+
+## Using
+* Clone the repo
+* Change into the cloned repo and create a folder `fs/`
+* Update `auto_install.conf` with a desired information about your specific install
+* Place any files you want included into your images (usually `install.site` and `rc.firsttime`)
+```sh
+cp install.site fs/
+mkdir fs/etc
+cp rc.firsttime fs/etc
+```
+
 ## Refs
 * https://www.openbsd.org/faq/faq4.html#site
 * https://github.com/ajacoutot/aws-openbsd