Add documentation

Fixes #7

Author: RobLoach

README.md

@@ -7,3 +7,66 @@ User contributed wrappers for ChaiScript.
 - Math: Adds common math methods to ChaiScript.
 - String ID: String hashing with [string_id](https://github.com/foonathan/string_id)
 - String Methods: Introduces some extra string methods to ChaiScript strings
+
+### Math
+
+The Math module adds some standard math functions to ChaiScript.
+
+#### Install
+``` cpp
+#include "chaiscript/extras/math.hpp"
+```
+``` cpp
+chaiscript::ChaiScript chai;
+auto mathlib = chaiscript::extras::math::bootstrap();
+chai.add(mathlib);
+```
+
+#### Usage
+
+``` chaiscript
+var result = cos(0.5f)
+```
+
+### String ID
+
+Adds [String ID](https://github.com/foonathan/string_id) support to ChaiScript.
+
+#### Install
+
+``` cpp
+#include "chaiscript/extras/string_id.hpp"
+```
+
+``` cpp
+auto string_idlib = chaiscript::extras::string_id::bootstrap();
+chai.add(string_idlib);
+```
+
+### String Methods
+
+Adds various string methods to extend how strings can be used in ChaiScript:
+- `string::replace(string, string)`
+- `string::trim()`
+- `string::split(string)`
+- `string::toLowerCase()`
+- `string::toUpperCase()`
+
+#### Install
+
+``` cpp
+#include "chaiscript/extras/string_methods.hpp"
+```
+
+``` cpp
+auto stringmethods = chaiscript::extras::string_methods::bootstrap();
+chai.add(stringmethods);
+```
+
+#### Usage
+
+``` chaiscript
+var input = "Hello, World!"
+var output = input.replace("Hello", "Goodbye")
+// => "Goodbye, World!"
+```