Update readme (#3)

* Adding Dockerfile

* Add information about exporting values

* Add readme

* Update documentation to fix CLI

* Update doc by fixing lint

README.md

@@ -1,23 +1,53 @@
 # Get Repository Statistics
 
-This script can help you find information about your repositories in your system
+GitHub CLI extensions are repositories that provide additional gh commands, and this GitHub CLI extension can help you find information about your repositories in your system.
+
+## Prerequisites
+
+- You need to have GitHub CLI installed by following this documentation: <https://github.com/cli/cli#installation>
+- You need to have an operating system to run shell script
+
+You need to either export these environment variables
+
+| Environment Variable name | Value |
+| ------------------------- | ----- |
+| GITHUB_TOKEN | GitHub Personal Access Token (PAT) with `admin:org`, `user:all`, and `repo:all` permissions
+| ORG_NAME | Organization name to run script |
+| GHE_URL | GitHub URL or GHES URL without HTTP or HTTPS |
+
+You can export these environment variables with following commands:
+
+```sh
+export GITHUB_TOKEN=<Your GitHub PAT>
+export ORG_NAME=<Your Org name>
+export GHE_URL=<Your GHE URL>
+```
+
+You can also create an environment variable named `.env` in following format:
+
+```sh
+GITHUB_TOKEN=<Your GitHub PAT>
+ORG_NAME=<Your Org name>
+GHE_URL=<Your GHE URL>
+```
+
+Then, you can source with a following command:
+
+```sh
+source .env
+```
 
 ## How to run
-- Download the folder `get-repo-statistics` to your local machine
-- Use `git-bash` to run the following commands
-- Change into the directory
-  - `cd get-repo-statistics`
-- Build the `Dockerfile`
-  - `docker build -t github/runner:latest -f Dockerfile .`
-- This will build the container image: `github/runner:latest` with the needed scripts and libraries inside
-- Run the container and map to a local folder to pull out data
-  - `docker run -it --entrypoint /bin/bash -v /tmp:/tmp github/runner:latest`
-  - This command will start the container and drop you into the running container, with the `/tmp` directory mounted to your personal machines `/tmp` directory
-- You can now run the script from the container
-  - `./get-repo-statistics.sh`
-- Give the script information about `url`, `token`, and `organization`
-
-## Input file
+
+Make sure you followed prerequisites and then follow this instruction.
+
+### Step 1: Install GitHub extension
+
+```sh
+gh extension install mona-actions/gh-repo-stats
+```
+
+### Input file
 If you want to run this over multiple Orgs, you can pass an `input file` when starting the script
 - `./get-repo-statistics.sh --input Org-file.csv`
 - This will read in a list of orgs and run over the list