Add 'flex-' prefix for 'start' & 'end' flex values

[Abogical]

Spec: https://www.w3.org/TR/css-align/#positional-values

'start' & 'end' values were added to replace the 'flex-start' & 'flex-end' respectively. Unfortunately at this time, only Safari & Firefox support these values, so we have to add the flex- prefix to them. This plugin does not add these values even with stage 0.

[romainmenke]

Looked into this and this seems unrelated to logical.

I am also unsure if start and end can be safely converted to flex-start and flex-end.
From what I can tell these are two different features that happen to have similar effects in some cases.

We would have to ask for clarification here.

[romainmenke]

@Abogical we can not add a plugin for this because it isn't a safe transform.

start and flex-start are not the same thing.
They only have the same effect within a flex context.

We can not determine from static CSS if align-items: start; will be applied on an element within a flex context.

It is best to use the correct values for each case. If your case requires flex-start you should use exactly that.

[Abogical]

Yeah it seems the specs may have changed since I last saw this. Thanks anyway!