hulk inclusion
category: doc
bugzilla: NA
CVE: NA

We need to document our rules of submitting patches to openEuler,
it contains the basic step of submitting patches, and unified patch
format.

This guideline is important for openEuler daily works, so I prefer
to place it into kernel root directory, it would be easy to access and
reference it.

Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Hanjun Guo <guohanjun@huawei.com>