Rename all CSS classes to use Title style names

[mirdaki]

There was no class naming scheme at the start of this project. As a result, the current names are kind of a mess and I'm sure the CSS rules are more complicated because of it. I purpose (though I'm open to other suggestions) that we adopt the Title naming scheme, because it is simple and clean.

We need to:

• Update all class and ID names, using the new naming scheme, in the HTML files and their corresponding CSS
• After verifying the old rules till work, reduce and simplify CSS rules using the new names. Make sure that the actual look of the page is not altered negatively
• Add a CSS style guide (it should go into the club-resources repo, but we need to link to it from here) that includes the naming scheme and anything else that makes sense

[logandgsmith]

Addressing this in #72.