Change README.md and add description

Author: Alexander Zutikov

README.md

@@ -1,6 +1,23 @@
 # NbgExrp
 
-**TODO: Add description**
+## Descripion
+```elixir
+	-h, --help
+	  Desc: Show help message
+	  Usage: nbg_exrp -h, nbg_exrp --help
+	-r, --rate
+	  Desc: Show current rate for USD
+	  Usage: nbg_exrp -r usd, nbg_exrp --rate usd
+
+	--all
+	  Desc: Shoo all currencies rates
+	  Usage: nbg_exp --all
+
+	-c, --convert
+	 Desc: Convert amount in currenty to GEL
+	 Usage: nbg_exrp -c 10 usd, nbg_exrp --conver 10 usd
+```
+
 
 ## Installation
 
@@ -10,12 +27,11 @@ by adding `nbg_exrp` to your list of dependencies in `mix.exs`:
 ```elixir
 def deps do
   [
-    {:nbg_exrp, "~> 0.1.0"}
+	{:nbg_exrp, "~> 0.1.0"}
   ]
 end
 ```
 
 Documentation can be generated with [ExDoc](https://github.com/elixir-lang/ex_doc)
 and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
 be found at [https://hexdocs.pm/nbg_exrp](https://hexdocs.pm/nbg_exrp).
-

lib/nbg_exrp/cli.ex

@@ -42,6 +42,10 @@ defmodule NbgExrp.CLI do
       Desc: Show current rate for USD
       Usage: nbg_exrp -r usd, nbg_exrp --rate usd
 
+    --all
+      Desc: Shoo all currencies rates
+      Usage: nbg_exp --all
+
     -c, --convert
      Desc: Convert amount in currenty to GEL
      Usage: nbg_exrp -c 10 usd, nbg_exrp --conver 10 usd