Update README.md with current documentation

README.md

@@ -2,41 +2,98 @@
 
 Dredge is a command line tool for working with the Docker Registry V2 API.
 
-## Configuration
-
-Dredge is configured using a simple TOML based configuration file format.
-By default, it will look in the default configuration location for your
-operating system i.e. on Linux this is `~/.config/dredge/dredge.toml`.
-
-You may also override the configuration file at the command line with the
-`-c` or `--config` argument.  The supplied argument must refer to an
-existing file.
-
-The format of the configuration file is simple, and contains only the
-base URL for the registry server.
-
-```toml
-registry_url = "https://localhost:5000"
-```
-
-If Dredge is run without a configuration file present, one will be created
-with the default configuration shown above.
-
 ## Usage
 
+```shell
+Dredge is a command line tool for working with the Docker Registry V2 API.
+
+Usage: dredge [OPTIONS] <REGISTRY> <COMMAND>
+
+Commands:
+  catalog  Fetch the list of available repositories from the catalog
+  tags     Fetch the list of tags for a given image
+  show     Show detailed information about a particular image
+  delete   Delete a tagged image from the registry
+  check    Perform a simple API Version check towards the configured registry endpoint
+  help     Print this message or the help of the given subcommand(s)
+
+Arguments:
+  <REGISTRY>
+          The host or host:port or full base URL of the Docker Registry
+
+Options:
+      --log-level[=<LEVEL>]
+          [default: info]
+          [possible values: trace, debug, info, warn, error, off]
+
+  -h, --help
+          Print help (see a summary with '-h')
+
+  -V, --version
+          Print version
+```
 ### Checking the API Version
 
-Performs a simple API version check.
+Perform a simple API Version check towards the registry endpoint
 
 ```sh
-dredge check
+Usage: dredge <REGISTRY> check
+
+Options:
+  -h, --help  Print help
 ```
 
 ### Fetch Repository List
 
-Fetch a sorted list of available repository names from the Registry's
-catalog.
+Fetch the list of available repositories from the catalog
 
 ```sh
-dredge catalog
+Usage: dredge <REGISTRY> catalog
+
+Options:
+  -h, --help  Print help
 ```
+
+### Listing tags for an image
+
+Fetch the list of tags for a given image
+
+```shell
+Usage: dredge <REGISTRY> tags <NAME>
+
+Arguments:
+  <NAME>  
+
+Options:
+  -h, --help  Print help
+```
+
+### Viewing details of a tagged image
+
+Show detailed information about a particular image
+
+```shell
+Usage: dredge <REGISTRY> show <IMAGE> [TAG]
+
+Arguments:
+<IMAGE>  
+[TAG]
+
+Options:
+-h, --help  Print help
+```
+
+### Deleteing a tagged image
+
+Delete a tagged image from the registry
+
+```shell
+Usage: dredge <REGISTRY> delete <IMAGE> <TAG>
+
+Arguments:
+<IMAGE>  
+<TAG>
+
+Options:
+-h, --help  Print help
+```