docs(nodejs): move branch references to main (#1174)

synthtool/gcp/templates/node_library/.github/generated-files-bot.yml

@@ -8,9 +8,9 @@ generatedFiles:
 - path: '.github/generated-files-bot.+(yml|yaml)'
   message: '`.github/generated-files-bot.(yml|yaml)` should be updated in [`synthtool`](https://github.com/googleapis/synthtool)'
 - path: 'README.md'
-  message: '`README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/master/.readme-partials.yaml'
+  message: '`README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/{{ metadata['repo']['default_branch'] }}/.readme-partials.yaml'
 - path: 'samples/README.md'
-  message: '`samples/README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/master/.readme-partials.yaml'
+  message: '`samples/README.md` is managed by [`synthtool`](https://github.com/googleapis/synthtool). However, a partials file can be used to update the README, e.g.: https://github.com/googleapis/nodejs-storage/blob/{{ metadata['repo']['default_branch'] }}/.readme-partials.yaml'
 ignoreAuthors:
 - 'gcf-owl-bot[bot]'
 - 'yoshi-automation'

synthtool/gcp/templates/node_library/README.md

@@ -10,7 +10,7 @@
 
 {{ metadata['repo']['release_level']|release_quality_badge }}
 [![npm version](https://img.shields.io/npm/v/{{ metadata['name'] }}.svg)](https://www.npmjs.org/package/{{ metadata['name'] }})
-[![codecov](https://img.shields.io/codecov/c/github/{{ metadata['repo']['repo'] }}/master.svg?style=flat)](https://codecov.io/gh/{{ metadata['repo']['repo'] }})
+[![codecov](https://img.shields.io/codecov/c/github/{{ metadata['repo']['repo'] }}/{{metadata['repo']['default_branch']}}.svg?style=flat)](https://codecov.io/gh/{{ metadata['repo']['repo'] }})
 
 {% if metadata['deprecated'] %}
 | :warning: Deprecated Module |
@@ -146,8 +146,8 @@ Contributions welcome! See the [Contributing Guide](https://github.com/{{ metada
 Please note that this `README.md`, the `samples/README.md`,
 and a variety of configuration files in this repository (including `.nycrc` and `tsconfig.json`)
 are generated from a central template. To edit one of these files, make an edit
-to its template in this
-[directory](https://github.com/googleapis/synthtool/tree/master/synthtool/gcp/templates/node_library).
+to its templates in
+[directory](https://github.com/googleapis/synthtool).
 
 ## License