Add a section about fixing references
Add a section about fixing references

I was very confused about where the `require('module',foo=bar)` syntax was coming from, and how to use it in my own modules.  <mikolalysenko> from #stackgl on freenode explained this to me in a conversation:
```
<micahf> when modules use the require(glsl-module,foo=bar) syntax, is that something built into glslify?
<micahf> i don't see that in the documentation, only in examples
<micahf> is it to make sure when the variable and function names get mogrified, that relationships between modules are preserved?
<mikolalysenko> micahf: that's right
<mikolalysenko> basically glslify pastes the code from the module into your project at that point, and renames all the free variables within that module
<micahf> mikolalysenko, okay, this stuff should be in the documentation!
<mikolalysenko> yeah, it should
<micahf> mikolalysenko, so just to clarify, if I use "foo=bar", it will pass bar from the local code into glsl-module as foo
<mikolalysenko> yes
<mikolalysenko> so the free variable foo in the module will be replaced with bar
<micahf> mikolalysenko, that makes sense.  are there any other tricks of the require(...) function?  can i pass in other options?
<mikolalysenko> nope, that is it
<micahf> mikolalysenko, pretty straightforward!
<mikolalysenko> the main reason for this feature is that it lets you emulate things like closures/first class functions
<mikolalysenko> for example if you want to write a raytracer, you can reuse your ray marching loop
<mikolalysenko> by having whatever implicit you are tracing go as an input into the ray marcher
<micahf> mikolalysenko, does glslify take care of the order of code?  or do I need to make sure bar is defined before the point when I do require(glsl-module,foo=bar) ?
<mikolalysenko> you need to make sure bar is declared before you import the module
<mikolalysenko> since it pastes the module in your code at that point
```
stackgl/glslify,stackgl/glslify