Add ROS Support page.

[nuclearsandwich]

This is based on the page that used to be at https://www.ros.org/support

I'm sure that there's more we can do but given how often this page is
cited it would be nice to have something up there.

[tfoote]

That content is here: https://www.ros.org/blog/getting-started/# If anything we should redirect it to there instead possibly?

[kscottz]

This is great and I really appreciate the help. I can handle styling the page, updating it, and adding a link to it in the footer/header. I'll merge it in next week along with a few other PRs. If you have anything else you want me to add, happy to take care of it.

[tfoote]

@kscottz The content is already there under the getting started header. And it's been updated for ROS 2 What I didn't realize was that the sub-heading was available via the url to the anchor Getting Started is the concatenation of two pages. Install and Support https://web.archive.org/web/20211019043340/https://www.ros.org/support/

We can split it back that way.

[nuclearsandwich]

I just updated the Support page to use the existing content from Getting Started.
What should be done with the Getting Started page?

As a side note, it's curious to me that the Getting Started page is considered a "blog post". Is that an intentional choice or should I contribute a change which makes a top-level getting-started page?

[tfoote]

Yeah, everything us currently listed as under "/blog" I ticketed it at #25 All the standard pages shouldn't go under blog.

[tfoote]

Can the "Getting Started" page use some sort of include to get both. Alternatively we could really use a redirect to maintain the old url but keep the structure.