This guide now lives at:
- https://learn.hashicorp.com/terraform#getting-started
...and terraform.io has been redirecting to there for quite a while. This commit
removes the extra copy so that the text of the two versions doesn't drift, and
updates existing links to point to the new location.
Although /intro/getting-started includes docs content, those pages currently
redirect to the Learn platform, and so shouldn't be affected by the large unfurl
image.