Learn Erlang in Y minutes

Draft about Erlang mostly taken from [Programming Erlang: Software for a Concurrent World](http://pragprog.com/book/jaerlang/programming-erlang) by @joearms.

Todo list:

- [x] comments
- [x] punctuation
- [x] variables
- [x] atoms
- [x] tuples
- [x] lists
- [x] pattern matching
- [x] module definition
- [x] function definition
- [x] list comprehension
- [x] guards
- [x] records
- [x] case expressions
- [x] if expressions
- [x] exceptions
- [ ] binaries
- [ ] compiling and running your program
- [ ] concurrency primitives
- [ ] handling errors in concurrent programs
- [ ] OTP introduction