Update documentation

Closes #37 
кажется, тут правильнее "assemblers" вместо "collectors"
тут, кажется, лучше сказать наоборот "Starting a new [BEM](http://bem.info/) project, what does any developer do?" -> "What does any developer do by starting a new project?"
"Unfortunately, and for bem-tools, and for enb" -> "Unfortunately it is rather time-consuming and prone to error process both for bem-tools and ENB.