Feature request: Support for faux bold and italic

[olivierbelzile]

We are trying to match text rendering from imagesharp to the display of a browser. One limitation that we are facing comes from the the lack of capability to generate bold and italic styles on fonts where only the regular style is available. On the web, font synthesis allows for various weights and oblique typefaces when using such fonts. Is there any plan to add these features to the library?

[christianrondeau]

Implementation proposed for faux italic: SixLabors/Fonts#542

[christianrondeau]

Implementation proposed for faux bold: SixLabors/Fonts#543

[JimBobSquarePants]

I've merged the PRs by @christianrondeau so there is a version of the functionality available in the nightlies, however I have made tweaks locally to ensure that we perfectly match browser behaviour as you can see below. I'll ship that with the rest of the changes coming for v3.1.