Shared header and footer
The header above and the footer below come from one file. Every Shluchim Office site loads the same file, so a change made once shows up on every site.
Add it to a site
In the page's <head>:
<script src="https://assets.shluchim.org/chrome/v1/chrome.js" defer></script>
Where the header and footer go:
<shluchim-header></shluchim-header>
... the page ...
<shluchim-footer></shluchim-footer>
Change a link or a menu
Edit the SITE object at the top of chrome/v1/chrome.js in the GitHub repo Shluchim-Office/shluchim-assets and push. Every site picks it up within about five minutes.