This PR adds the API reference documentation for `tvm.s_tir.analysis`.
`tvm.s_tir.analysis` functions use Var in their type annotations, which
exists in both `tvm.tirx` and `tvm.relax`. The existing disambiguator
uses common module prefix to pick the right one, but `tvm.s_tir` shares
no prefix with either. The new `tvm_module_type_preference` mapping
tells the disambiguator to prefer `tvm.tirx` types for `tvm.s_tir.*`
modules.
Shushi Hong