update README.md with some docs for playbook

README.md

@@ -1,2 +1,21 @@
 # nitter-ansible
 Ansible playbook to install nitter
+
+## Requirements
+- Latest stable version of Ansible (this was tested with Ansible 2.10.7)
+- A Ubuntu 20.04 LTS server with a public IP
+- A (sub)-domain name for Nitter with a valid A record with aforementioned IP
+
+## How To Use
+
+- Copy group_vars/all.sample to group_vars/all and edit the following variables:
+  - NITTER_DOMAIN - your Nitter domain [MANDATORY]
+  - NITTER_PORT - the port you want Nitter to run on, you can leave this on 8080 if you are unsure
+  - NITTER_HMAC - you can generate a value for this on your Ansible host with pwgen -s 24 1
+  - ACME_ACCOUNT_EMAIL - for SSL certificate expiry notices from LE if renewal fails
+- Make a Ansible hosts file that looks like this:
+```
+[nitter]
+nitter.example.com
+```
+- Run the playbook with `ansible-playbook -i hosts site.yml`