[Docs] Update visualization documentation

[alexfrancoeur]

With 5.4 I think we need to make a few more adjustments to the visualization documentation.

In comparison to our current documentation it looks as if X/Y charts replaced line, area and bar charts. I'm not confident this terminology is the best to use as we don't reference anywhere else. I'd be comfortable just calling the section Line, Area and Bar chart. Now that we are grouping visualization types into categories, does it make sense to group in a similar fashion?

Basic charts

• Line, Area and Bar
• Heat Map
• Pie Chart

Data

• Data table
• Metric

Maps

• Tile Map

Time Series

• Timelion
• Visual builder (experimental)

Other

• Markdown
• Tag Cloud

I'd also like to link to timelion and the new time series visual builder docs #11215

Similarly do we want to use the in-product terminology for options?

Rather than options we could have Metric & Axes and Panel Settings

There are also some screenshots that could be updated with geocentroid support and newly available configuration options in the getting started documentation for visualizations. This would be a good place to highlight the fact that we can now chart multiple chart types on the same visualization.

@tbragin any other thoughts?