Added some documentation to the readme

README.md

@@ -1,3 +1,79 @@
 # Going
 
 Small CLI tool for working with AWS. This tool is mostly used to log in to ECS containers.
+
+# Usage
+
+All commands will prompt for an AWS profile defined in the shared AWS config file `$HOME/.aws/config`.
+You can use the `-p, --profile` flag to specify a profile and not be prompted.
+
+All prompts have fuzzy searching.
+
+## shell command
+
+You can connect to an ECS container using the `shell` command.
+This command will make sure the cached SSO credentials are valid and if not will attempt to refresh them.
+
+```shell
+going shell -p staging
+```
+
+This will prompt you to select a cluster, service, task (if more than 1 is running), and a container.
+
+If the ExecuteCommand agent isn't running in the container you can use the `--ssm` flag to use SSM directly.
+
+```
+Open a shell to a container in ECS
+
+Usage:
+  going shell [flags]
+
+Flags:
+  -c, --cluster string     The cluster name
+  -r, --container string   The container name
+  -h, --help               help for shell
+  -s, --service string     The service name
+      --ssm                Use SSM directly to get a shell
+
+Global Flags:
+  -p, --profile string   The AWS profile to use
+```
+
+## sso command
+
+The `sso` command by itself will print the AWS `access_key`, `secret_key`, and `token` credentials.
+Adding the `-e, --env` flag will output the credentials as environment variables that can be pasted into a `.env` file.
+
+This command has multiple sub-commands for login/logout and an automatic way of replacing AWS environment variables.
+
+```shell
+going sso --env
+```
+
+### replace command
+
+The `replace` command will try to replace the environment variables for the AWS credentials in `.env` files.
+The command takes either a list of files as positional arguments or if no flags exist it will try `$PWD/.env`.
+
+```shell
+going sso replace /project1/.env /project2/.env
+```
+
+The way this is done currently is pretty simple, it will only update keys that exist in the file and not add missing ones.
+The keys it updates are `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`, and `AWS_SESSION_TOKEN`.
+
+### login command
+
+This command will perform a full SSO login, ignoring the cached SSO credentials.
+
+```shell
+going sso login
+```
+
+### logout command
+
+This command will perform a logout of the current SSO session by telling AWS to invalidate the session and deleting the cached credential file.
+
+```shell
+going sso logout
+```