github.io documentation restructuring

[kta-intel]

Description: This PR restructures the current github.io. Contents are intact and migrated from the old documentation with minor updates and additions

Objective:

1. Easier for a user to navigate (get started guide, feature list, etc.)
2. Easier for developer team to maintain and expand upon
3. Better aligns with other Intel AI software documentation while drawing inspiration from ecosystem FL documentation

Added:

1. get started guide (using existing examples and installation instructions)
2. release notes (keep users in the loop with changes in a more self-contained way)
3. blogs & publications (for better promotion to dev community)
4. features (collated existing docs into one place to better highlight features)