i2pd.md: Add mention of Rocky/EPEL version for COPR repo

[neelchauhan]

Author checklist (Completed by original Author)

• Good fit for the Rocky Linux project? Title and Author Metatags inserted ?
• If applicable, steps and instructions have been tested to work
• Initial self-review to fix basic typos and grammar completed

Rocky Documentation checklist (Completed by Rocky team)

• 1st Pass (Document is good fit for project and author checklist completed)
• 2nd Pass (Technical Review - check for technical correctness)
• 3rd Pass (Detailed Editorial Review and Peer Review)
• Final approval (Final Review)

[github-actions]

Test results for 0442956:

Number of broken URLs: 11

URL,RESULT,FILENAME
 https://reddit.com/r/rockylinux,failed,release_notes/9_1.md
 https://reddit.com/r/rockylinux,failed,release_notes/8_7.md
 https://reddit.com/r/rockylinux,failed,release_notes/8_5.md
 https://reddit.com/r/rockylinux,failed,release_notes/9_3.md
 https://reddit.com/r/rockylinux,failed,release_notes/9_2.md
 https://reddit.com/r/rockylinux,failed,release_notes/9_0.md
 https://reddit.com/r/rockylinux,failed,release_notes/8_6.md
 https://reddit.com/r/rockylinux,failed,release_notes/8_9.md
 https://reddit.com/r/rockylinux,failed,release_notes/8_8.md
 http://planet.i2p,failed,guides/proxies/i2pd.md
 https://www.linode.com/docs/guides/beginners-guide-to-lxd-reverse-proxy,failed,guides/containers/lxd_web_servers.md