Add og images to talks - Githubissues

This PR builds upon #36 and adds images to all the talks to be shown on embed.

This PR also fixes quite a few other details:

It uses the correct links for og tags
It supports deploy domains in image links (you can test the og tags on the temporary netlify domain)
It fixes the tag on the pages</li> <li>It extracts some of the duplicate logic in templates</li> </ul> <p>_Note: The images are generated based using <a rel="noreferrer nofollow" target="_blank" href="https://www.sketch.com/">Sketch</a>, the <a rel="noreferrer nofollow" target="_blank" href="https://www.datapopulator.com/">Data Populator plugin</a> and the generated <code>/content/_data/2020/talks_simple.json</code> with the attached <a rel="noreferrer nofollow" target="_blank" href="https://github.com/datproject/public-events/files/4957872/20200722_dat-event-2020-banner.zip"><code>20200722_dat-event-2020-banner.sketch</code></a><em> and later optimized using <a rel="noreferrer nofollow" target="_blank" href="https://pngmini.com/">ImageAlpha</a> to produce 128bit color pngs </em>(roughly 1/5th of the size)_.</p> </div> </div> <div class="comment"> <div class="user"> <a rel="noreferrer nofollow" target="_blank" href="https://github.com/martinheidegger"><img src="https://avatars.githubusercontent.com/u/914122?v=4" />martinheidegger</a> commented <strong> 4 years ago</strong> </div> <div class="markdown-body"> <p>Merging early, so we have it ready for the next meeting. Please revert if its a problem.</p> </div> </div> <div class="page-bar-simple"> </div> <div class="footer"> <ul class="body"> <li>© <script> document.write(new Date().getFullYear()) </script> Githubissues.</li> <li>Githubissues is a development platform for aggregating issues.</li> </ul> </div> <script src="https://cdn.jsdelivr.net/npm/jquery@3.5.1/dist/jquery.min.js"></script> <script src="/githubissues/assets/js.js"></script> <script src="/githubissues/assets/markdown.js"></script> <script src="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/highlight.min.js"></script> <script src="https://cdn.jsdelivr.net/gh/highlightjs/cdn-release@11.4.0/build/languages/go.min.js"></script> <script> hljs.highlightAll(); </script> </body> </html>

dat-ecosystem / public-events

Add og images to talks #37