Add more information about package and speed

Closes #1

Author: praveenperera

README.md

@@ -2,6 +2,22 @@
 
 Parse RSS feeds very quickly
 
+* This is rust NIF built using [rustler](https://github.com/rusterlium/rustler)
+* Uses the [RSS](https://crates.io/crates/rss) crate to do the actual RSS parsing
+
+**Speed**
+
+Currently this is already much faster than most of the pure elixir/erlang packages out there. In benchmarks there is speed improvements anyway between **2.85x - 22.05x** over the next fastest package [feeder_ex](https://github.com/manukall/feeder_ex). 
+
+Compared to the slowest elixir options ([feed_raptor](https://github.com/merongivian/feedraptor), [elixir_feed_parser](https://github.com/fdietz/elixir-feed-parser)), FastRSS was sometimes **127.21x** faster and used **2091.61x** less memory. See [benchmarks](#benchmark) below.
+
+
+This could probably be made even faster by properly using [serde_rustler](https://github.com/sunny-g/serde_rustler) to directly convert the [`rss:Channel`](https://docs.rs/rss/1.9.0/rss/struct.Channel.html) into an elixir map (PRs welcome)
+
+Currently we do this very naively, the process is:
+  1. On the rust side we serialize the [`rss:Channel`](https://docs.rs/rss/1.9.0/rss/struct.Channel.html) it into a JSON string using [`serde_json`](https://docs.serde.rs/serde_json/)
+  2. Then on the elixir side we deserialize the JSON string into a elixir map using [`Jason`](https://github.com/michalmuskala/jason)
+
 ## Installation
 
 This package is available on [hex](https://hex.pm/packages/fast_rss).