Add new QXmpp logo (#528)

This commit adds a new logo for the project. The logotype includes
the alphabet 'Q' written in Morse Code, this is inspired by the use of
morese code in the logotype of a downstream project - Kaidan. The
logotype resembles a chat speech bubble, hinting that this library is
used to facilitate chat communication.

README.md

@@ -3,14 +3,16 @@ SPDX-FileCopyrightText: 2009 Manjeet Dahiya <manjeetdahiya@gmail.com>
 
 SPDX-License-Identifier: CC0-1.0
 -->
-
 <h1 align="center">
-    QXmpp
+<picture>
+    <img alt="QXmpp logo" src="./logo.svg" height="150">
+</picture>
+</h1>
+<p align="center">
     <a href="https://xmpp.org/extensions/xep-0459.html">
         <img alt="XMPP:2022 Client IM Mobile+ Compliance Badge" src="https://img.shields.io/badge/XMPP%3A2022%20Client-Core%20IM%20Mobile%2B-green">
     </a>
-</h1>
-
+</p>
 <p align="center">
     <a href="https://github.com/qxmpp-project/qxmpp/actions">
         <img alt="Build Status" src="https://github.com/qxmpp-project/qxmpp/workflows/tests/badge.svg">

doc/doap.xml

@@ -24,6 +24,7 @@ SPDX-License-Identifier: CC0-1.0
     <support-forum rdf:resource='xmpp:qxmpp@muc.kaidan.im?join'/>
     <license rdf:resource='https://github.com/qxmpp-project/qxmpp/tree/master/LICENSES'/>
     <language>en</language>
+    <schema:logo rdf:resource='https://raw.githubusercontent.com/qxmpp-project/qxmpp/master/logo.svg'/>
     <programming-language>C++</programming-language>
     <os>Android</os>
     <os>iOS</os>

logo.svg.license

@@ -0,0 +1,4 @@
+SPDX-FileCopyrightText: 2023 Raghavendra Kamath <raghu@raghukamath.com>
+
+SPDX-License-Identifier: CC-BY-SA-4.0
+