Updated README.

Author: Son-HNguyen

README.md

@@ -110,7 +110,7 @@ Demos
 # Mobile Support Extension
 
 
-### New features
+## New features
 
 
 The current 3DCityDB-Web-Map-Client is equipped with an extension that provides better support while operating on mobile devices. 
@@ -121,53 +121,53 @@ Some of the most important mobile features enabled by this extension are listed
 In order to make the best use of the limited screen real-estate available on mobile devices, some elements are removed or hidden from the web client, 
 such as credit texts and logos, as well as some of Cesium's built-in navigation controls that can easily be manipulated using touch gestures. 
 <p align="center">
-<img src="theme/img/mobile_homepage.png" />
+<img src="theme/img/mobile_homepage.PNG" />
 </p>
 
 * **Visual adjustments:**
     * The main toolbox now scales to fit to the screen size. In case of excess lines/length, the toolbox becomes scrollable (see picture below).
     <p align="center">
-    <img src="theme/img/mobile_toolbox.png" />
+    <img src="theme/img/mobile_toolbox.PNG" />
     </p>
 
     * The infobox displayed when a city object (e.g. building) is clicked is now displayed in fullscreen with scrollable contents, as illustrated below.
     <p align="center">
-    <img src="theme/img/mobile_infobox.png" />
+    <img src="theme/img/mobile_infobox.PNG" />
     </p>
 
     * The loading icon is now shown as a horizontal bar at the bottom of the screen (highlighted by the green box in the picture below).
     <p align="center">
-    <img src="theme/img/mobile_loading.png" />
+    <img src="theme/img/mobile_loading.PNG" />
     </p>
 
 * Most importantly: **The introduction of a GPS button** (located on the top right corner in the view toolbar) providing new functionalities involving user's current location and orientation. Namely: 
     * GPS "snapshot" (single-click): shows the user's current position and orientation,
     <p align="center">
-    <img src="theme/img/GPS_on.png" />
+    <img src="theme/img/GPS_off.png" width="25%" />
     </p> 
 
     * Real-time Compass Tracking  (double-click): periodically shows the user's current orientation with fixed location,
     <p align="center">
-    <img src="theme/img/GPS_on_ori.png" />
+    <img src="theme/img/GPS_on_ori.png" width="25%" />
     </p> 
 
     * Real-time Compass Tracking + Position (triple-click) or the "First-person View" mode: periodically shows the user's current orietation and position.
     <p align="center">
-    <img src="theme/img/GPS_on_pos_ori.png" />
+    <img src="theme/img/GPS_on_pos_ori.png" width="25%" />
     </p> 
 
     * To disable real-time tracking, simply either click on the button again to return to "snapshot" mode 
 or hold the button for 1 second, the camera will then ascend to a higher altitude of the current location.
 
-### Demos
+## Demos
 
 
 For demo and testing purposes, this mobile extension is also available under:
 * [first-person view link](https://www.3dcitydb.org/3dcitydb-web-map/first-person-view/3dwebclient/index.html?gltf_version=0.8&title=3DCityDB-Web-Map-Client&shadows=false&terrainShadows=0&latitude=48.14841421296063&longitude=11.567992899981103&height=288.04731096361564&heading=328.7476197616152&pitch=-79.2212906741018&roll=359.46114981350894&layer_0=url%3Dhttps%253A%252F%252Fwww.3dcitydb.org%252F3dcitydb%252Ffileadmin%252Fmydata%252FMunich_Demo%252FBuildings_glTF%252FBuildings_glTF_MasterJSON.json%26name%3DMUC%26active%3Dtrue%26spreadsheetUrl%3Dhttps%253A%252F%252Ffusiontables.google.com%252Fdata%253Fdocid%253D1KE3odY92wmpwdyUs6osYhNPgRtI9W3GOQyuyHfp3%2523rows%253Aid%253D1%26cityobjectsJsonUrl%3D%26minLodPixels%3D140%26maxLodPixels%3D1.7976931348623157e%252B308%26maxSizeOfCachedTiles%3D200%26maxCountOfVisibleTiles%3D200)
 * [debug-mode view link](https://www.3dcitydb.org/3dcitydb-web-map/first-person-view/3dwebclient/index.html?gltf_version=0.8&title=3DCityDB-Web-Map-Client&shadows=false&terrainShadows=0&latitude=48.14841421296063&longitude=11.567992899981103&height=288.04731096361564&heading=328.7476197616152&pitch=-79.2212906741018&roll=359.46114981350894&layer_0=url%3Dhttps%253A%252F%252Fwww.3dcitydb.org%252F3dcitydb%252Ffileadmin%252Fmydata%252FMunich_Demo%252FBuildings_glTF%252FBuildings_glTF_MasterJSON.json%26name%3DMUC%26active%3Dtrue%26spreadsheetUrl%3Dhttps%253A%252F%252Ffusiontables.google.com%252Fdata%253Fdocid%253D1KE3odY92wmpwdyUs6osYhNPgRtI9W3GOQyuyHfp3%2523rows%253Aid%253D1%26cityobjectsJsonUrl%3D%26minLodPixels%3D140%26maxLodPixels%3D1.7976931348623157e%252B308%26maxSizeOfCachedTiles%3D200%26maxCountOfVisibleTiles%3D200&viewMode=debug).
 
 
-# Notes
+## Notes
 
 
 The mobile extension makes use of the Geolocation API and the DeviceOrientation API in HTML5.