feat: Create separate page for Pastebins

[redoomed1]

Changes proposed in this PR:

• Create a separate recommendation page for pastebins
  • This PR kicks off a multipart effort to address Split up Productivity Tools page #2596
  • No changes to the content ported from the Productivity Tools page
  • Changes for the new recommendation page
    • Added page cover: a photo by Chris Ried at https://unsplash.com/photos/a-computer-screen-with-a-bunch-of-code-on-it-ieic5Tq8YMk; any suggestions for alternative page covers are welcome!
    • Added content-paste Material Design sidebar icon
    • Added page introduction and one-sentence description
• Add Pastebins section in tools.md and move PrivateBin entry to it
• Delete "Paste services" section from the Productivity Tools page

This is my first PR that involves an image upload, so I welcome any feedback in this department! I went over https://www.privacyguides.org/en/meta/uploading-images, but there isn't any guidance on WebP images, which is the preferred format for cover images.

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  1) I am the sole author of this work. 2) I agree to grant Privacy Guides a perpetual, worldwide, non-exclusive, transferable, royalty-free, irrevocable license with the right to sublicense such rights through multiple tiers of sublicensees, to reproduce, modify, display, perform, relicense, and distribute my contribution as part of this project. 3) I have disclosed any relevant conflicts of interest in my post. 4) I agree to the Community Code of Conduct.

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[redoomed1]

How I went about optimizing the Unsplash image linked in my initial post:

1. Download it as a .jpg file
2. Use cwebp to convert it to a WebP file by running cwebp -size 300000 [image-name].jpg -o pastebins.webp

-size specifies target size in bytes. I set it to 300,000 bytes (300 KB) because, of all the cover images on the site, the one for the Desktop Browsers page is the largest at 305 KB.

[jonaharagon]

Good note, we should probably document WebP optimization. IIRC all the existing images were a pre-set quality level but I don't remember what that setting was. I'll do that later.