Update gamma page

[ScanMountGoat]

Show a comparison image for what a "gamma fixed" UI image looks like in an image editor and in game. The important concept is that the in game renderer is roughly equivalent to applying gamma 0.4545 to the input image. Saving as SRGB is necessary for most color textures and recommended for UI to preserve shadow detail.

Input Textures (various formats) -> conversion to linear (different for SRGB) -> rendered image (still linear) -> final result (SRGB)

[ScanMountGoat]

It's also worth adding images for what happens when textures have incorrect gamma. The website should mention that SSBH Editor can check for this and link to the validation error page.

[ScanMountGoat]

The render images and graphs can be combined into a single wider image. The square aspect ratio takes up too much of the screen at the moment.