Add "comparison to alternatives" page

[jennymahmoudi]

One way to help people understand Flox is to give them some comparisons to alternatives that they may be familiar with. This would have simple summaries as if answering a question being asked on hackernews or reddit.

One page to cover a few technologies like...

"Flox vs Docker"
"Flox vs Devbox"
"Flox vs mise"
etc

We have some work to draw from like https://flox.dev/blog/is-flox-an-alternative-to-containers/

There's some strategic implications to what we choose to highlight here, so consider whether we want to include the items listed under https://github.com/flox/product/blob/main/competitors/competitors.md#competitors-we-want-to-avoid-being-compared-to

[vorburger]

Compare with https://devenv.sh as well, perhaps?