Clarify gravity and buoyancy movement description

Removed redundant toggle information for gravity and buoyancy movement.

Merge pull request #7 from AngelJumbo/gradient

Gradient options

in runtime change colors and the party mode

increase or decrease the rim with shift+i and shift+d (I just can't s…

…leep, help)

Updated -h option

Fix typo

Fix typo

Update README.md