Documentation Improvements

[melvincarvalho]

The following changes should be made to improve the documentation:

1. "block chain" -> "blockchain"
2. "keypair" -> "key pair"
3. "gitmark" -> "git-mark"

Consider adding a brief explanation of what a genesis transaction is and why it's important.

Provide more context on what "marking" means in this context.

Clarify the relationship between the genesis transaction and the current git HEAD.

Consider providing an example command for sending coins to an address.

Explain what "advance the genesis transaction" means and why it's necessary.

Consider adding a note about the importance of keeping the private key secure.

These changes and additions will enhance the clarity and completeness of the documentation, making it easier for users to understand and follow the instructions.