fix og:image at issue level

[eliselavy]

Now we have. hardcoded value in:

https://github.com/C2DH/journal-of-digital-history/blob/develop/public/index.html

with several issue running in parallel how to do it?

Social media cover for issue are here:

https://github.com/C2DH/journal-of-digital-history/tree/develop/public/img/issues/social-media

to take also from api - raw ul

[danieleguido]

the og:image in the index.html file is the image that appears when referring to the root url, so it can be changed manually according to the editorial needs: call for papers, new issue, etc.. as it was done in v2.4.6

[danieleguido]

still todo (I put low priority for now):

• create a helmet for the issue (similar to src/components/ArticleV2/ArticleHelmet)
• load the helmet when src/pages/Articles got the issue id params (i.e. when url is https://journalofdigitalhistory.org/en/issue/jdh002) see routing rule in App component:

  journal-of-digital-history/src/App.js

  Line 149 in f854ce1

  <Route path={`${path}/issue/:id`} component={ArticlesPage} />