[Documentation Suggestion] Minor clarity/ease-of-use changes to documentation

[RepeatGitHub]

Here's a few suggestions that could be cool for the documentation:

• Having the Documentation option on the site under Custom Attack lead to here.
• In the Combat.md file of documentation, making sure to specify at the top that the middle of the screen is (320, 240) and the total screen size is 640x480.
• Under SansSlam in Attacks.md, being sure to mention the directions of each slam (since usually it takes experimentation to figure out that 0 is right, 1 is down, 2 is left, and 3 is up, and would be more convenient for newcomers to custom attacks to not need to experiment.)