feat(docs): Update legacy section

docs/legacy/porting.md

@@ -2,17 +2,18 @@
 
 Here you can find a list of primers on how to port from old versions to the current version. Some versions are lumped together since that particular version never saw much usage.
 
-|    From -> To      |               Primer                    |
-|:------------------:|:----------------------------------------|
-| 1.12 -> 1.13/1.14  | [Primer by williewillus][112to114]      |
-| 1.14 -> 1.15       | [Primer by williewillus][114to115]      |
-| 1.15 -> 1.16       | [Primer by 50ap5ud5][115to116]          |
-| 1.16 -> 1.17       | [Primer by 50ap5ud5][116to117]          |
-| 1.19.2 -> 1.19.3   | [Primer by ChampionAsh5357][1192to1193] |
-| 1.19.3 -> 1.19.4   | [Primer by ChampionAsh5357][1193to1194] |
-| 1.19.4 -> 1.20.0   | [Primer by ChampionAsh5357][1194to120]  |
-| 1.20.4 -> 1.20.5/6 | [Primer by ChampionAsh5357][1204to1205] |
-| 1.20.6 -> 1.21     | [Primer by ChampionAsh5357][1206to121]  |
+|    From -> To         |               Primer                    |
+|:---------------------:|:----------------------------------------|
+| 1.12 -> 1.13/1.14     | [Primer by williewillus][112to114]      |
+| 1.14 -> 1.15          | [Primer by williewillus][114to115]      |
+| 1.15 -> 1.16          | [Primer by 50ap5ud5][115to116]          |
+| 1.16 -> 1.17          | [Primer by 50ap5ud5][116to117]          |
+| 1.19.2 -> 1.19.3      | [Primer by ChampionAsh5357][1192to1193] |
+| 1.19.3 -> 1.19.4      | [Primer by ChampionAsh5357][1193to1194] |
+| 1.19.4 -> 1.20.0      | [Primer by ChampionAsh5357][1194to120]  |
+| 1.20.4 -> 1.20.5/6    | [Primer by ChampionAsh5357][1204to1205] |
+| 1.20.6 -> 1.21/1.21.1 | [Primer by ChampionAsh5357][1206to121]  |
+| 1.21.1 -> 1.21.2      | [Primer by ChampionAsh5357][1211to1212] |
 
 [112to114]: https://gist.github.com/williewillus/353c872bcf1a6ace9921189f6100d09a
 [114to115]: https://gist.github.com/williewillus/30d7e3f775fe93c503bddf054ef3f93e
@@ -23,3 +24,4 @@ Here you can find a list of primers on how to port from old versions to the curr
 [1194to120]: https://gist.github.com/ChampionAsh5357/cf818acc53ffea6f4387fe28c2977d56
 [1204to1205]: https://gist.github.com/ChampionAsh5357/53b04132e292aa12638d339abfabf955
 [1206to121]: https://gist.github.com/ChampionAsh5357/d895a7b1a34341e19c80870720f9880f
+[1211to1212]: https://github.com/neoforged/.github/blob/main/primers/1.21.2/index.md