Add note on reducing vendor size for AWS SDK

[aromka]

Added note about removing unused AWS services to reduce bundle size.

[mnapoli]

Thanks! The note already exists here, maybe it can be made more visible by:

• turning the small note into a sub-section (that way we have a title that we can link to)
• updating your diff so that it links to the existing section (to avoid duplicating the info, but making sure all readers can find it more easily)

What do you think?

[aromka]

Oh cool, yes, I think it should be more visible. The only note I saw was on using AsyncAws and completely missed that one.