Update README.md

README.md

@@ -98,7 +98,25 @@ These are currently unimplemented ideas that we plan on adding:
 These images are signed with sisgstore's [cosign](https://docs.sigstore.dev/cosign/overview/). You can verify the signature by downloading the `cosign.pub` key from this repo and running the following command:
 
     cosign verify --key cosign.pub ghcr.io/ublue-os/ubuntu
+
+## Building Locally
 
+1. Clone this repository and cd into the working directory
+
+       git clone https://github.com/ublue-os/bluefin.git
+       cd bluefin
+
+1. Make modifications if desired
+
+1. Build the image (Note that this will download and the entire image)
+
+       podman build . -t bluefin
+
+1. [Podman push](https://docs.podman.io/en/latest/markdown/podman-push.1.html) to a registry of your choice.
+1. Rebase to your image to wherever you pushed it:
+
+       sudo rpm-ostree rebase ostree-unverified-registry:whatever/bluefin:latest
+
 ## Frequently Asked Questions
 
 > What about codecs?