v5.1.0

* Removed commented out list styles.
* Moved `.text-small`, `.text-large`, and `.text-muted` to `_overrides.scss` for better cascade inheritance.
* Updated SVG process to allow for multiple SVG files.
* Increased `h4`, `h5`, and `h6` font size to `1em`.
* Adjusted styling of `.icon` class in `_svg.scss` for less specificity and easier overriding.
* Renamed `_svgs.scss` to `_svg.scss`.