Fix social media logo visibility by using dedicated PNG image for og:image

[Copilot]

The social media sharing (og:image) was using the inverted white logo (org-i.svg) which doesn't show well on most social media backgrounds. This PR fixes the issue by adding custom Open Graph meta tags that use a dedicated PNG image (og-image.png) specifically created for social media sharing while keeping the white logo in the sidebar.

Problem

The Sphinx documentation was configured with html_logo = "_static/images/org-i.svg" (inverted/white logo) for display on the blue sidebar background. However, this same logo was being used for social media sharing (og:image), making it nearly invisible on typical social media backgrounds.

Solution

Added custom meta tags in the page template (docs/_templates/page.html) to override the og:image with a dedicated PNG image:

<meta property="og:image" content="{{ pathto('_static/images/og-image.png', 1) }}">
<meta property="og:image:type" content="image/png">
<meta property="og:image:alt" content="Ilustrace organizátora Python akcí">

Result

• ✅ Social media sharing now uses the dedicated PNG image (og-image.png) optimized for social media
• ✅ Sidebar continues to display the white logo (org-i.svg) on blue background
• ✅ Proper relative paths are generated using Sphinx's pathto() function
• ✅ All pages include the correct og:image meta tags with PNG format for better compatibility

Fixes #15.

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[Copilot]

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[honzajavorek]

Nepoužívej prosím XHTML tagy, dej tam obyčejné HTML5 tagy bez těch zavírátek na konci.

[honzajavorek]

@copilot přečti si můj komentář v review a oprav to

[Copilot]

Nepoužívej prosím XHTML tagy, dej tam obyčejné HTML5 tagy bez těch zavírátek na konci.

Done! Converted the XHTML-style meta tags to HTML5 format by removing the closing slashes. The tags now use proper HTML5 syntax. Commit: b2777ef

[honzajavorek]

@copilot Nakonec jsem se rozhodl, že by v tom meta tagu mělo být spíš PNG. Vyrobil jsem PNG přímo pro tento účel a jmenuje se og-image.png, pushnul jsem ho tady do té tvojí větve. Změň prosím cestu k souboru.

[Copilot]

@copilot Nakonec jsem se rozhodl, že by v tom meta tagu mělo být spíš PNG. Vyrobil jsem PNG přímo pro tento účel a jmenuje se og-image.png, pushnul jsem ho tady do té tvojí větve. Změň p...

Updated the og:image meta tag to use the new og-image.png file and changed the content type to image/png. The documentation builds successfully and the meta tags are correctly generated. Commit: 1f7b8b1