[website] Fix redirect for links with a trailing slash
Summary:
This should redirect from the following urls:
- https://www.bitcoinabc.org/2022-09-07-avalanche-staking-tutorial.html
- https://www.bitcoinabc.org/2022-09-07-avalanche-staking-tutorial
- https://www.bitcoinabc.org/2022-09-07-avalanche-staking-tutorial/
Test Plan:
bundle exec jekyll serve
Reviewers: #bitcoin_abc, Mengerian
Reviewed By: #bitcoin_abc, Mengerian
Differential Revision: https://reviews.bitcoinabc.org/D12322