docs: Add backend vs2019 to table in Builtin-options.md [skip ci]
@@ -69,7 +69,7 @@ Using the option as-is with no prefix affects all machines. For example:
| Option | Default value | Description | Is per machine |
| ------ | ------------- | ----------- | -------------- |
| auto_features {enabled, disabled, auto} | auto | Override value of all 'auto' features | no |
-| backend {ninja, vs,<br>vs2010, vs2015, vs2017, xcode} | ninja | Backend to use | no |
+| backend {ninja, vs,<br>vs2010, vs2015, vs2017, vs2019, xcode} | ninja | Backend to use | no |
| buildtype {plain, debug,<br>debugoptimized, release, minsize, custom} | debug | Build type to use | no |
| debug | true | Debug | no |
| default_library {shared, static, both} | shared | Default library type | no |
