updated README

README.md

@@ -2,13 +2,37 @@
 gocast is a program for downloading podcasts from acast.com via rss feed.
 
 ## Build
-```
+```shell
 git clone https://github.com/philippdrebes/gocast.git
 cd gocast
 make build
 ```
 
 ## Install
-```
+```shell
 make install
+```
+
+## Usage
+```shell
+Hello Gocast!
+usage: gocast [-h|--help] -n|--name "<value>" [-o|--output "<value>"]
+              [-l|--list] [-i|--index <integer>] [--all] [--latest]
+
+              gocast is a program for downloading podcasts from acast.com via
+              rss feed.
+
+Arguments:
+
+  -h  --help    Print help information
+  -n  --name    Podcast name e.g. letstalkaboutcarsyo for
+                http://rss.acast.com/letstalkaboutcarsyo
+  -o  --output  Specifies where downloaded episodes will be saved to
+  -l  --list    List all episodes
+  -i  --index   Download a single episode via index. Run the 'list' command in
+                order to get the index of the desired episode. Default: -1
+      --all     Download all episodes
+      --latest  Download the latest episode
+
+
 ```