static/frontend: fix homepage link when running in LocalMode

Change the homepage link based on whether we are running in LocalMode. If pkgsite or frontend are running in LocalMode, set the href link to "/", otherwise keep "https://go.dev".

Fixes golang/go#60916

Change-Id: I363edef5195fd613392f64f26d0bc732fdf90dbf
GitHub-Last-Rev: 364ac96
GitHub-Pull-Request: #67
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/504795
Reviewed-by: Robert Findley <[email protected]>
Reviewed-by: Peter Weinberger <[email protected]>
TryBot-Result: kokoro <[email protected]>
Auto-Submit: Robert Findley <[email protected]>
Run-TryBot: Robert Findley <[email protected]>

Author: amine7536

static/frontend/styleguide/styleguide.tmpl

@@ -42,7 +42,7 @@
   </nav>
   <div class="go-Main-headerContent">
     <div class="go-Main-headerTitle">
-      <a class="go-Main-headerLogo" href="https://go.dev/" aria-hidden="true" tabindex="-1" data-gtmc="header link"
+      <a class="go-Main-headerLogo" href="{{if .LocalMode}}/{{else}}https://go.dev/{{end}}" aria-hidden="true" tabindex="-1" data-gtmc="header link"
           aria-label="Link to Go Homepage">
         <img height="78" width="207" src="/static/shared/logo/go-blue.svg" alt="Go">
       </a>

static/frontend/unit/_header.tmpl

@@ -53,7 +53,7 @@
 
 {{define "unit-header-title"}}
   <div class="go-Main-headerTitle js-stickyHeader">
-    <a class="go-Main-headerLogo" href="https://go.dev/" aria-hidden="true" tabindex="-1" data-gtmc="header link" aria-label="Link to Go Homepage">
+    <a class="go-Main-headerLogo" href="{{if .LocalMode}}/{{else}}https://go.dev/{{end}}" aria-hidden="true" tabindex="-1" data-gtmc="header link" aria-label="Link to Go Homepage">
       <img height="78" width="207" src="/static/shared/logo/go-blue.svg" alt="Go">
     </a>
     <h1 class="UnitHeader-titleHeading" data-test-id="UnitHeader-title">{{.Title}}</h1>