docs: clarify pre-155 tx requirement with EIP-155 reference

[nikolaysamoil0ff]

Motivation:

• The deployment documentation uses the outdated term “pre-155 transaction” without explanation.
• Make the documentation more self-sufficient and useful for developers unfamiliar with the historical context of Ethereum.

Solution:
Added a link to the EIP-155 specification at the first mention to provide immediate context and the opportunity to delve deeper.