Fix links to lighthouse docs (#2391)

* Fix links to lighthouse docs

* Update goldens

internals/testdata/notifier_test/test_format_email_body__mozdev_links_mozilla.html

@@ -27,7 +27,7 @@
 <p>Next steps:</p>
 <ul>
   <li>Check existing
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-core/audits"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/core/audits"
        >Lighthouse audits</a> for correctness.</li>
 
 

internals/testdata/notifier_test/test_format_email_body__mozdev_links_non_mozilla.html

@@ -27,7 +27,7 @@
 <p>Next steps:</p>
 <ul>
   <li>Check existing
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-core/audits"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/core/audits"
        >Lighthouse audits</a> for correctness.</li>
 
 

internals/testdata/notifier_test/test_format_email_body__new.html

@@ -21,7 +21,7 @@
   <li>Try the API, write a sample, provide early feedback to eng.</li>
   <li>Consider authoring a new article/update for /web.</li>
   <li>Write a
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/docs/recipes/custom-audit"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/docs/recipes/custom-audit"
        >new Lighthouse audit</a>. This can help drive adoption of an API
     over time.
   </li>

internals/testdata/notifier_test/test_format_email_body__update_no_changes.html

@@ -27,7 +27,7 @@
 <p>Next steps:</p>
 <ul>
   <li>Check existing
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-core/audits"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/core/audits"
        >Lighthouse audits</a> for correctness.</li>
 
 

internals/testdata/notifier_test/test_format_email_body__update_with_changes.html

@@ -27,7 +27,7 @@
 <p>Next steps:</p>
 <ul>
   <li>Check existing
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-core/audits"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/core/audits"
        >Lighthouse audits</a> for correctness.</li>
 
 

templates/new-feature-email.html

@@ -17,7 +17,7 @@
   <li>Try the API, write a sample, provide early feedback to eng.</li>
   <li>Consider authoring a new article/update for /web.</li>
   <li>Write a
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/docs/recipes/custom-audit"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/docs/recipes/custom-audit"
        >new Lighthouse audit</a>. This can help drive adoption of an API
     over time.
   </li>

templates/update-feature-email.html

@@ -23,7 +23,7 @@
 <p>Next steps:</p>
 <ul>
   <li>Check existing
-    <a href="https://github.com/GoogleChrome/lighthouse/tree/master/lighthouse-core/audits"
+    <a href="https://github.com/GoogleChrome/lighthouse/tree/main/core/audits"
        >Lighthouse audits</a> for correctness.</li>
 
 {% if moz_link_urls %}