docs: fix stale content, dead links, and missing nav entries

README.md

@@ -11,7 +11,7 @@ To work on and change these documents, you'll need git, python, and pip.
 
 - CentOS
     ```sh
-    sudo yum install python-pip
+    sudo dnf install python3 python3-pip
     ```
 
 Fork the repo

docs/blog/mfa_mandatory.md

@@ -1,7 +1,7 @@
 # PeeringDB Will Require MFA and API Keys to Log In
 *March 13, 2025*
 
-You must have a [second factor](/howto/enable_require_2fa/) to log in to PeeringDB starting on 1 July 2025. If you automate updates using [our API](/api_specs/), you'll need to use an [API Key](/howto/api_keys/).
+You must have a [second factor](/howto/authenticate/#multi-factor-authentication-mfa) to log in to PeeringDB starting on 1 July 2025. If you automate updates using [our API](/api_specs/), you'll need to use an [API Key](/howto/api_keys/).
 
 But anonymous usage will not be going away. You can query the website or API without authenticating. This change will impact users who make updates or need access to contact information published in PeeringDB.
 

docs/blog/peeringdb_2022_user_survey.md

@@ -11,7 +11,7 @@ We had about 250 responses to last year’s survey which helped guide our produc
 * Added FIDO U2F 2FA support to [www.peeringdb.com](https://www.peeringdb.com/)
 * Normalized place names
 
-We’ve also published more documents in our [HOWTO documentation series](/howto/). 
+We’ve also published more documents in our [HOWTO documentation series](/howtos/). 
 
 Steve McManus, PeeringDB Product Committee Chair, says: "*The 2021 survey helped us focus development where it was most needed. We used it to develop our roadmap. We are still implementing things we have learned from previous surveys but want your input on how we should adapt. Please take a few moments of their time to help us make PeeringDB a better service!*”