[gimp-web] Update development download page for Linux/Flatpak.

[Jehan <jehanp src gnome org>]

commit fef497d5c2519602b543daba6257b7035f2d21fe
Author: Jehan <jehan girinstud io>
Date:   Sun Nov 8 14:36:21 2020 +0100

    Update development download page for Linux/Flatpak.
    
    We must install both the flathub and flathub-beta repositories as the
    runtime will be in the stable flathub repo (I actually changed to use a
    beta runtime but was told this is not the right way so I'll likely
    revert).
    
    Also combining <code> with <pre> should actually be the right way to
    handle multi-line of code apparently.

 .../newgimp/templates/downloads-development.html   | 35 +++++++++++++++-------
 1 file changed, 25 insertions(+), 10 deletions(-)
---
diff --git a/themes/newgimp/templates/downloads-development.html 
b/themes/newgimp/templates/downloads-development.html
index ef01e63c..d1dbb158 100644
--- a/themes/newgimp/templates/downloads-development.html
+++ b/themes/newgimp/templates/downloads-development.html
@@ -63,14 +63,28 @@
         automatic builds). If there are no development releases, the
         latest stable release will be provided instead in this
         repository.</p>
-        <p>Install with following command lines:
+
+        <p>
+            <span class='win-button'>
+                <a href="https://flathub.org/beta-repo/appstream/org.gimp.GIMP.flatpakref";>
+                    Install GIMP development flatpak
+                </a>
+            </span>
+        </p>
         <p>
-        <code>
+        Flatpak build available in: <strong>x86-64 and AArch64</strong>.
+        </p>
+
+        <h3>Flatpak additional instructions</h3>
+
+        <p>If the link above doesn't open your software installer,
+        install with following command lines:
+        <p>
+        <code><pre>
           flatpak remote-add --user flathub-beta https://flathub.org/beta-repo/flathub-beta.flatpakrepo
-        </code>
-        <br/>
-        <code>
+          flatpak remote-add --user flathub https://dl.flathub.org/repo/flathub.flatpakrepo
           flatpak install --user flathub-beta org.gimp.GIMP
+        </pre></code>
         </code>
         </p>
         <p>
@@ -94,13 +108,14 @@
         version:</em>
         </p>
         <p>
-        <code>
+        <code><pre>
           flatpak make-current --user org.gimp.GIMP stable
-        </code>
-        <br/>
-        <code>
           flatpak make-current --user org.gimp.GIMP beta
-        </code>
+        </pre></code>
+        </p>
+        <p>
+        <em>You may also create shortcuts running these specific
+        commands.</em>
         </p>
 
 <!--