chore(README): prepare for v0.9.0 (aquasecurity#507)

* chore(README): prepare for v0.9.0

* chore(README): replace 'artifacts' with 'containers and other artifacts'

* chore: more detail for filesystem scan

Co-authored-by: Liz Rice <[email protected]>

* chore: more detail for embedding Trivy in the Dockerfile

Co-authored-by: Liz Rice <[email protected]>

* Update README.md

Co-authored-by: Liz Rice <[email protected]>

* Update README.md

Co-authored-by: Liz Rice <[email protected]>

* chore(README): add a new line

* chore(README): revert TOC and add blog links

* chore(README): add Microscanner link

Co-authored-by: Liz Rice <[email protected]>