readme: fix download image & chevrons instructions

This patch modifies the image link of the "Download with cx.ring"
badge.
It also takes care of escaping chevrons to display the build
instructions properly on some markdown viewers such as the Github one.

Change-Id: If6487010f80222516b4390675b6fd40e94fa1cf4
Reviewed-by: Alexandre Lision <alexandre.lision@savoirfairelinux.com>

README.md

@@ -10,7 +10,7 @@ For more information about the ring project, see the following:
 
 | App | CI | Packaging
 | :-: | :-: | :-:
-| [![Download from ring.cx](https://img.shields.io/badge/download-cx۔ring-blue.svg)](https://ring.cx/en/download/mac-osx) | [![Build Status](https://test.savoirfairelinux.com/buildStatus/icon?job=ring-client-macosx)](https://test.savoirfairelinux.com/job/ring-client-macosx/) | [![Build Status](https://test.savoirfairelinux.com/buildStatus/icon?job=ring-packaging-client-macosx)](https://test.savoirfairelinux.com/job/ring-packaging-client-macosx/)
+| [![Download from ring.cx](https://img.shields.io/badge/download-cx.ring-blue.svg)](https://ring.cx/en/download/mac-osx) | [![Build Status](https://test.savoirfairelinux.com/buildStatus/icon?job=ring-client-macosx)](https://test.savoirfairelinux.com/job/ring-client-macosx/) | [![Build Status](https://test.savoirfairelinux.com/buildStatus/icon?job=ring-packaging-client-macosx)](https://test.savoirfairelinux.com/job/ring-packaging-client-macosx/)
 
 Requirements
 =============
@@ -42,16 +42,16 @@ Build Client
 
 1. mkdir build && cd build
 
-2. export CMAKE_PREFIX_PATH=<dir_to_qt5>
+2. export CMAKE_PREFIX_PATH=\<dir_to_qt5\>
 
 Now generate an Xcode project with CMake:
-3. cmake ../ -DCMAKE_INSTALL_PREFIX=<libringclient_install_path> -G Xcode
+3. cmake ../ -DCMAKE_INSTALL_PREFIX=\<libringclient_install_path\> -G Xcode
 4. open Ring.xcodeproj/
 5. Build and run it from Xcode. You can also generate the final Ring.app bundle.
 
 You can also build it from the command line:
 
-3. cmake ../ -DCMAKE_INSTALL_PREFIX=<libringclient_install_path>
+3. cmake ../ -DCMAKE_INSTALL_PREFIX=\<libringclient_install_path\>
 4. make
 5. open Ring.app/
 
@@ -63,7 +63,7 @@ If you want to create the final app (self-containing .dmg):
 Notes:
 
 By default the client version is specified in CMakeLists.txt but it can be
-overriden by specifying -DRING_VERSION=<num> in the cmake command line.
+overriden by specifying -DRING_VERSION=\<num\> in the cmake command line.
 
 You can specify a custom ringtone folder containing audio files (only)
 with -DRINGTONE_DIR option