Server docs building

[heckj]

Do Not Merge

Updates the guide to building packages for Swift Server

Motivation:

Updates the guide to building packages for Swift Server, resolves swiftlang/docs#19

Modifications:

Revise to align to the outline in swiftlang/docs#19 and add some additional guidance on inspecting binary executables using file with examples to show how the different build options can be compared.

Result:

Perhaps the easiest way to view this content would be to check out this PR and running the branch locally, so you get a good HTML preview of the proposed article updates:

gh pr checkout 1277
make build
make website
open http://localhost:4000/documentation/server/guides/building/
make clean

[heckj]

going to repurpose this to apply these updates into a repo within the docs repository

[heckj]

closing in favor of swiftlang/docs#31