goreleaser: add experimental homebrew tap support

Think it's right, but not sure whether it'll actually work.
Tomorrow, if it functions, we'll declare it no longer experimental.

Co-Authored-By: sketch <hello@sketch.dev>
Change-ID: s5126ee115c362b2ck
diff --git a/.github/workflows/release-build.yml b/.github/workflows/release-build.yml
index 5dcce37..c068c88 100644
--- a/.github/workflows/release-build.yml
+++ b/.github/workflows/release-build.yml
@@ -89,6 +89,7 @@
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           SELFUPDATE_SIGNING_KEY: ${{ secrets.SELFUPDATE_ED25519_SIGNING_KEY }}
+          HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.HOMEBREW_GITHUB_API_TOKEN }}
 
 
 
diff --git a/.goreleaser.yml b/.goreleaser.yml
index 9957af1..df600f1 100644
--- a/.goreleaser.yml
+++ b/.goreleaser.yml
@@ -57,3 +57,24 @@
     name: sketch
   draft: false
   prerelease: false
+
+brews:
+  - name: sketch
+    url_template: "https://github.com/boldsoftware/sketch/releases/download/{{ .Tag }}/{{ .ArtifactName }}"
+    url_headers:
+      - "Accept: application/octet-stream"
+      - 'Authorization: bearer #{ENV["HOMEBREW_GITHUB_API_TOKEN"]}'
+    commit_author:
+      name: goreleaserbot
+      email: bot@goreleaser.com
+    commit_msg_template: "Brew formula update for {{ .ProjectName }} version {{ .Tag }}"
+    directory: Formula
+    homepage: "https://sketch.dev"
+    description: "Sketch is an agentic coding tool. It draws the 🦉"
+    license: "Apache-2.0"
+    test: |
+      system "#{bin}/sketch -version"
+    repository:
+      owner: boldsoftware
+      name: homebrew-tap
+      token: "{{ .Env.HOMEBREW_GITHUB_API_TOKEN }}"