docs: Current List of Mocking Limitations is incomplete

[jenisys]

Describe the bug The current list of FSeam mocking limitations (what is not working) is incomplete.

My exploration of FSeam lead to the following list of limitations (that are not described):

• inline-methods are not mockable (no MockData generated)
• Mocking SameClass from multiple namespaces should cause problems in one test-executable (ClassesToMock: namespace1::ClassA, namespace2::ClassA)
• Ctor() with arg-ref(s) or arg(s) cause compile-errors (#22)
• Const-GetterMethod()/NonConst-GetterMethod pairs cause problems/compile-errors
• Same-Method variants with different parameter-signatures should cause problems, like: ClassA::method1(int), ClassA::method1(std::string), ClassA::method1(int, std::string)...
• TBC: const-reference return-types cause problems in FSeamMockData (const not-removed in return-type)
• TBC: const-value return-types cause problems in FSeamMockData (const not-removed in return-type)

Expected behavior Update the docs (README, limitations.md) to better serve FSeam users and their expectations what works and what not.

Additional context AFAIK the current limitations are described here:

• docs/limitations.md
• docs/future.md (partially: planned features and fixed problems)
• Issue #22 -- Ctor with arg(s)

[FreeYourSoul]

Thank you for the contribution, I will update the README in consequences and check if there is a way to generate the appropriate code for const returned type.