docs: replace links to pacta.rmi.org pages with precise URLs, once they are available for tabs

[jacobvjk]

we are trying to link to specific tabs on two pacta.rmi.org pages, namely

• "Methodology and Documents" and "Training Materials" on https://pacta.rmi.org/pacta-for-banks-2020/
• "Metrics" on https://pacta.rmi.org/pacta-for-investors/

However the URLs will direct people to a page that shows the "Overview" tab by default. Since there is no sub-url for the other tabs right now, documentation has to add long-winded descriptions what tab people should navigate to. This should be replaced with a clear URL to the respective tabs, once the website is updated top enable that

[jdhoffa]

This should be available soon™️

[cjyetman]

Weirdly, I did discover that you can get to the page for the specific sub-tabs with these links, though it shows the page content outside of the "normal" PACTA for Banks site structure

https://pacta.rmi.org/pacta-for-banks-2020/software/
https://pacta.rmi.org/pacta-for-banks-2020/methodology-and-supporting-materials/
https://pacta.rmi.org/pacta-for-banks-2020/training-materials/

not sure if these are stable, or advisable to use

[cjyetman]

and the one for P4I Metrics is... wait for it....
https://pacta.rmi.org/pacta-for-investors/metrics/