add help entry to readme

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "himalaya"
-description = "📫 Minimalist CLI mail client"
+description = "📫 Minimalist CLI email client"
 version = "0.1.0"
 authors = ["soywod <clement.douin@posteo.net>"]
 edition = "2018"

README.md

@@ -1,3 +1,28 @@
-# Himalaya
+# 📫 Himalaya
 
-📫 Minimalist CLI mail client, written in Rust.
+Minimalist CLI email client, written in Rust.
+
+```bash
+himalaya --help
+```
+
+```help
+Himalaya 0.1.0
+soywod <clement.douin@posteo.net>
+📫 Minimalist CLI email client
+
+USAGE:
+    himalaya [SUBCOMMAND]
+
+FLAGS:
+    -h, --help       Prints help information
+    -V, --version    Prints version information
+
+SUBCOMMANDS:
+    forward    Forwards an email by its UID
+    help       Prints this message or the help of the given subcommand(s)
+    query      Prints emails filtered by the given IMAP query
+    read       Reads an email by its UID
+    reply      Replies to an email by its UID
+    write      Writes a new email
+```

src/main.rs

@@ -24,7 +24,7 @@ fn main() {
 
     let matches = App::new("Himalaya")
         .version("0.1.0")
-        .about("📫 Minimalist CLI mail client")
+        .about("📫 Minimalist CLI email client")
         .author("soywod <clement.douin@posteo.net>")
         .subcommand(
             SubCommand::with_name("read")