* 1358 Link to 'Settings for etcd tuning' no longer valid
updates dead link to new URL
* updated etcd version links
2.0-2.4 was tricky, I opted for etcd v3.3 as it's identical to the text on v3.4 except for a single clarifying heading
* update link in v2.5 to etcd v3.3 to cover downstream
* other 3.4 files in /docs
* other 3.4 files in /v2.9
* other 3.4 files in /v2.8
* other 3.4 files in /v2.7
* other 3.4 files in /v2.6
* other 3.4 files in /v2.5
* other 3.4 files in /v2.0-2.4
* rm'ing '.0' from URLs
* update v2.6 links to account for differing etcd versions
* chinese links
* 999 Clarify support and stipulations for use of firewall in documentation
added scarier warning about firewalld usage
* revised language slightly
* Update docs/how-to-guides/advanced-user-guides/open-ports-with-firewalld.md
Co-authored-by: Sunil Singh <sunil.singh@suse.com>
* versioning, updated link, & abbreviated warning for v2.0-2.4
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Co-authored-by: Sunil Singh <sunil.singh@suse.com>