Indeed, documentation on field formatters in 4.1 is light (I just logged issue 4299 to improve it).
To accomplish number formatting in 4.1, you can do the following:
- In Settings, go to the index with the field in question
- On the right-hand side under "Controls" column click the Edit icon next to the field you want to format
- If it's a numeric field, in the "Format" dropdown you'll see "Number" as one of the options
- Change the default to the following numeral.js pattern 0,0.[00]
- Click Update Field
After this, all visualizations using this field will only show two decimal points.
