Clean up code block styles

Does the following changes to the styles:

• Removes border from code blocks
• Removes corner radius from code blocks
• Decreases font-size of code blocks + inline code
• Set background colour for inline code
• Add a small padding for inline code now that it has a background
• Adds a material-design-card-ish drop shadow to code blocks

In addition, it also changes the content in the following ways:

• Ensures all code blocks use triple backticks instead of indenting
• Specify a syntax-highlighting language hint for most code blocks (usually bash but sometimes python or xml)
• Minor formatting changes to some docs pages (e.g. unfortunately placed hyphen rendering as a list when it shouldn't)

Open to any suggestions, but hopefully this is an improvement:

• "Build Server Setup" in master
• "Build Server Setup" in this branch

Fixes #61 (closed).