Remove support for Node.js 12

Closes GH-28.

Author: remcohaszing

.github/workflows/main.yml

@@ -17,7 +17,7 @@ jobs:
     strategy:
       matrix:
         node:
-          - lts/erbium
+          - lts/fermium
           - node
   windows:
     name: ${{matrix.node}}
@@ -32,5 +32,5 @@ jobs:
     strategy:
       matrix:
         node:
-          - lts/erbium
-          - node
+          - lts/fermium
+          - lts/gallium

readme.md

@@ -19,7 +19,7 @@ about what unified can do.
 ## Install
 
 This package is [ESM only](https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c):
-Node 12+ is needed to use it and it must be `import`ed instead of `require`d.
+Node 14+ is needed to use it and it must be `import`ed instead of `require`d.
 
 [npm][]: