[gnome-calculator] Use markdown format for image embeds in README and adjust list formatting

[Robert Roth <robertroth src gnome org>]

commit f08324588d7ed798b2096c1871eda1723fb71e4f
Author: Roger <sachanroger gmail com>
Date:   Mon Sep 2 19:20:13 2019 +0000

    Use markdown format for image embeds in README and adjust list formatting

 README.md | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)
---
diff --git a/README.md b/README.md
index 3e0a9dbf..640e1d91 100644
--- a/README.md
+++ b/README.md
@@ -2,14 +2,11 @@
 
 Calculator is an application that solves mathematical equations and is suitable as a default application in 
a Desktop environment.
 
-<a href='https://flathub.org/apps/details/org.gnome.Calculator'><img width='240' alt='Download on Flathub' 
src='https://flathub.org/assets/badges/flathub-badge-i-en.png'/></a>
+[![Download on 
Flathub](https://upload.wikimedia.org/wikipedia/commons/thumb/a/a6/Flathub-badge-en.svg/240px-Flathub-badge-en.svg.png)](https://flathub.org/apps/details/org.gnome.Calculator)
 
 ## Useful links
 
 - Homepage: <https://wiki.gnome.org/Apps/Calculator>
-
 - Report issues: <https://gitlab.gnome.org/GNOME/gnome-calculator/issues/>
-
 - Donate: <https://www.gnome.org/friends/>
-
 - Translate: <https://wiki.gnome.org/TranslationProject>
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