Add the description of kernel data structure(hlist_head and hlist_node or hash table)


The issue references kernel data structures hlist_head and hlist_node, likely for the 'linux-insides' book. Start by locating existing documentation on linked lists or hash tables in the repository. Review the image provided to understand the intended content. Determine where to add the description, possibly in a chapter about kernel data structures. Ensure the explanation aligns with the book's style and technical depth.

Written by the indexing model from the issue text.