Control vertical alignment separately from horizontal alignment

[8BitJonny]

Is your feature request related to a problem? Please describe.

As already discussed in #24 I want to control vertical alignment of the generated text separately from the horizontal alignment.

Currently we have dominant-baseline="middle" when center is set to "true" and dominant-baseline="auto" when its not.
Meaning the text is vertically top aligned by default and when center=true the text is both vertically and horizontally centered

Describe the solution you'd like

Expose dominant-baseline as a query param and control it like valign=top or valign=center

Describe alternatives you've considered

Currently there are no alternatives to controlling the vertical alignment