Removed "About SPIFFE header" for consistency with style and format of SPIRE repo. Fixed broken links.
Removed "About SPIFFE header" for consistency with style and format of SPIRE repo.
Fixed broken links.

Signed-off-by: Andres Vega <8ccb8a3f7ac5bd9c4f1ab74cb453f7f32903fb1b@scytale.io>

spiffe/spiffe