readme: add some more Q&A's and a limitation

README.md

@@ -154,6 +154,8 @@ Limitations
   schedule(), will fail to apply at runtime.
 - Patches which change functions that are only called in the kernel init path
   will have no effect (obviously).
+- Currently, kernel module functions can't be patched -- only functions in the
+  base kernel image.
 
 
 Frequently Asked Questions
@@ -232,6 +234,19 @@ We hope to make the following changes to other projects:
 
 We do have plans to implement something like that.
 
+**Q. What kernels are supported?**
+
+kpatch needs gcc >= 4.6 and Linux >= 3.7 for use of the -mfentry flag.
+
+**Q. Is it possible to remove a patch?**
+
+Yes.  Just unload the patch module and the original function will be restored.
+
+**Q. Can you apply multiple patches?**
+
+Yes.  Also, a single function can even be patched multiple times if needed.
+
+
 Demonstration
 -------------