docs(website): add support matrix

[jitingxu1]

Adding support matrix for ibisml Step, there are two ways to collect information for this:

• Execute each step against the actual backend.
  • We need to setup the actual backend to do this
• Compile each the expressions in step to check if it is compilable.
  • IbisML step consist of expression and python code, it needs strategy to extract the expression from Step, which looks ugly and unnecessary for the function itself.

We picked the second option. I am open to put the matrix in any position.

Here is the matrix: