chore: semantic-release config updates

* semantic release will monitor main branch instead of master (default)
* remove semantic-release as an explicit dependency (it is referenced as an explicit version in CI/build yaml)
* remove master as a monitored dest branch for CI

.github/workflows/build.yml

@@ -2,9 +2,9 @@ name: build
 
 on:
   push:
-    branches: [main, master]
+    branches: [main]
   pull_request:
-    branches: [main, master]
+    branches: [main]
 
 jobs:
   lint:

README.md

@@ -88,4 +88,4 @@ To trigger a release use a Conventional Commit following [Angular Commit Message
 
 Copyright © 2017 [Scott Willeke](https://github.com/activescott).
 
-This project is [MIT](https://github.com/activescott/serverless-http-invoker/blob/master/LICENSE) licensed.
+This project is [MIT](https://github.com/activescott/serverless-http-invoker/blob/main/LICENSE) licensed.