Add legato-version tag to 20.08.0 index.html
Add legato-version tag to 20.08.0 index.html

Resolves: LE-15796
Change-Id: I5739400ee552547e4a23edd8a8ce2a0715876e6d

legatoproject/legato-docs,legatoproject/legato-docs,legatoproject/legato-docs