Update home page message for the other browser case (#5866)

* Update home page message for the other browser case

1. Remove irrelevant comment.
2. Clarify that Firefox for desktop is needed for profiling which should eliminate confusion on, for example, Firefox for iOS.
3. Update download link, remove hardcoded en-US locale.

* Update translation key

Author: fatadel

locales/en-US/app.ftl

@@ -377,8 +377,8 @@ Home--record-instructions =
     keyboard shortcuts. The icon is blue when a profile is recording.
     Hit <kbd>Capture</kbd> to load the data into profiler.firefox.com.
 
-Home--instructions-content =
-    Recording performance profiles requires <a>{ -firefox-brand-name }</a>.
+Home--instructions-content2 =
+    Recording performance profiles requires <a>{ -firefox-brand-name } for desktop</a>.
     However, existing profiles can be viewed in any modern browser.
 
 Home--fenix-instructions-directly =

src/components/app/Home.tsx

@@ -230,7 +230,6 @@ type PopupInstallPhase =
 class HomeImpl extends React.PureComponent<HomeProps, HomeState> {
   constructor(props: HomeProps) {
     super(props);
-    // Start by suggesting that we install the add-on.
     let popupInstallPhase = 'other-browser';
 
     if (_isFirefox()) {
@@ -570,16 +569,15 @@ class HomeImpl extends React.PureComponent<HomeProps, HomeState> {
           <div>
             <DocsButton />
             <Localized
-              id="Home--instructions-content"
+              id="Home--instructions-content2"
               elems={{
-                a: <a href="https://www.mozilla.org/en-US/firefox/new/" />,
+                a: <a href="https://www.firefox.com" />,
               }}
             >
               <p>
                 Recording performance profiles requires{' '}
-                <a href="https://www.mozilla.org/en-US/firefox/new/">Firefox</a>
-                . However, existing profiles can be viewed in any modern
-                browser.
+                <a>Firefox for desktop</a>. However, existing profiles can be
+                viewed in any modern browser.
               </p>
             </Localized>
             <Localized

src/test/components/__snapshots__/Home.test.tsx.snap

@@ -975,9 +975,9 @@ exports[`app/Home renders the information screen for other browsers 1`] = `
           <p>
             Recording performance profiles requires 
             <a
-              href="https://www.mozilla.org/en-US/firefox/new/"
+              href="https://www.firefox.com"
             >
-              ⁨Firefox⁩
+              ⁨Firefox⁩ for desktop
             </a>
             .
 However, existing profiles can be viewed in any modern browser.