Some TODOs #7
Description
Some TODOs:
1- Rename "Pactus Blockchain documentation" to "Pactus Documentation"
2- Remove "📑 Documentation" link. It is redundant
3- "Get Started" needs to be in center and have margin
4- Add "Learn More" with different color next to "Get Started" and links to https://docs.pactus.org/docs/concepts/