Update link for SPDX license identifiers page (#1440)
Update link for SPDX license identifiers page (#1440)

The SPDX website has migrated from spdx.org to spdx.dev, and also an updated
page was created with more specific details about creating and using SPDX
short-form license identifiers in code. This updates to the new page.

Signed-off-by: Steve Winslow <9ce5770b3bb4b2a1d59be2d97e34379cd192299f@swinslow.net>
linuxfoundation/cii-best-practices-badge,linuxfoundation/cii-best-practices-badge,linuxfoundation/cii-best-practices-badge,coreinfrastructure/best-practices-badge,coreinfrastructure/best-practices-badge,coreinfrastructure/best-practices-badge,coreinfrastructure/best-practices-badge,linuxfoundation/cii-best-practices-badge