Upgrading from 1.11 - nothing to change. Your config.yml is kept as it is, and the settings 1.12 adds (server-language, min-gate-distance) are appended with their defaults the first time it loads: messages stay English until a player's client language has a lang file, and gates can still be built anywhere. From 1.10 or earlier, read the 1.11.0 upgrade note below first: an unedited config.yml is replaced there. A first install needs none of this.

• Messages in your players' language: chat messages follow each player's client language, falling back to server-language and then English; put a lang/<code>.yml in the plugin folder to add or reword one, and /wormhole lang export [code] writes a starter file. More messages become translatable each release; sign text stays English.
• Reload the config without a restart: /wormhole config -reload lists each setting it changed, names any value it refused and keeps the old one.
• Switch a gate shape off: /wormhole gate shapes disable <shape> and enable stop and allow building it without deleting its file; gates already standing keep working.
• A minimum distance between gates: min-gate-distance refuses a gate built too close to another in its world; wormhole.build.mindistance.bypass exempts. Off until set.
• Fixes: log-level: off no longer stops the plugin loading, shape commands refuse a name that leaves the shapes folder, a doubled apostrophe in the mirror capture messages is a single one, and a far-side capture is logged once.

Full changelog