[e.cash] Add anchor links to sections

Summary: as per https://reviews.bitcoinabc.org/T3241 adding some ids to be used for anchor links in some places

Test Plan:
preview the site and test out the links, for example
/ecash-brand#logos
/ecash-brand#colors
/ecash-brand#fonts
/faq#1 - /faq#15
/wealth-redefined#wealth-redefined
/wealth-redefined#our-why
/wealth-redefined#our-inspiration
/wealth-redefined#project-development
/#roadmap

Reviewers: #bitcoin_abc, bytesofman

Reviewed By: #bitcoin_abc, bytesofman

Subscribers: bytesofman

Differential Revision: https://reviews.bitcoinabc.org/D14296