Add related examples to docs and website

[joshka]

Problem

There have been a few questions recently about layout related things in discord. Many of the questions can be answered easily by looking at one of the examples. We don't yet have VHS tapes / gifs of these linked in the README, and they're not linked in the docs / website.

Solution

• Create any missing VHS tapes for each example - https://github.com/ratatui-org/ratatui/tree/main/examples/vhs
• Create / update any out of date gifs and upload to the images branch
• Add the example to the examples README
• Link to the example from each relevant main widget / layout doc comment
• Link to the examples from each relevant concept page in the website

[kdheepak]

In addition, I think layouts that are very common could use copy paste friendly docs on the website.

[kdheepak]

Related: #845, #1014

[joshka]

Related: #845, #1014

Ha, thanks past Joshka. :D