[SUGGESTION] add 'prefix' option in the same way 'suffix' is available

[CharliW90]

Lots of use cases for having something shown before the value, as a prefix. For example, many currrencies put the symbol first (e.g. £150.00 or €300,00) as well as some other measurements (e.g. V for climbing grades, such as V5)

[guibranco]

@CharliW90 working on this here: guibranco/progressbar#6

[guibranco]

-> https://progress-bar.xyz/300/?prefix=€&suffix=