* we now accept a lot more types of contributions and have improved the documentation.
* add link to the kernel porting guide from the readme.
* small updates to the op porting guide.
* Add files from TfLite
Added batch_matmul.h and tensor_utils_common.h that are needed for the BATCH_MATMUL operator.
* Add FAQ section
Add frequently asked questions section with regard to memory allocation and tensor structure manipulation.
bug=Add FAQ to reference op porting document #383
Co-authored-by: Advait Jain <advaitjain@users.noreply.github.com>
