Improved some of the website copy

* Refers to "the designer" now, instead of a mix of "designer" and "the
designer"
* Refers to developers, as a plural
* Refers to the designer as "they", the designer does not have a gender
* No longer refers to the prototype as 'he'
* Got rid of etc. as its meaning is derived from "such as"
* Workflow description section 2 now ends with a full stop.
* "Applied by the designer" is now "Implemented by the designer"
* Getting  patters in your site -> should be "into your site"
* "included it" -> "include it" as it is present tense
* "Github" is now "GitHub"
Merge pull request #207 from adamtheturtle/master

Improved some of the website copy