Doc: fixed several minor doc issues

- \brief statements
- snippet specification syntax
- folder specification issue

Task-number: QTBUG-31177
Change-Id: I853d08775c8eb43441a1edefed1a40d55b673a66
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>

doc/src/getting-started/examples.qdoc

@@ -28,6 +28,7 @@
 /*!
     \page qtexamplesandtutorials.html
     \title Qt Examples And Tutorials
+    \brief Explains step by step basic Qt programming
 
     \section1 Tutorials
 

doc/src/getting-started/installer-README.qdoc

@@ -86,9 +86,9 @@ tools, for example:
 
 The development tools are located in the directory
 \e{<install_dir>}/\e{<version>}/\e{<compiler>}/bin. For Windows, the MinGW
-toolchain is placed in \e{<install_dir>}\Tools. You can run them from Qt Creator
-or from the command line. You can also launch some of them as standalone
-applications.
+toolchain is placed in \e{<install_dir>}\\Tools. You can run
+them from Qt Creator or from the command line. You can also launch some of
+them as standalone applications.
 
 \section1 Running Example Applications
 

doc/src/qmlapp/firststepsqml.qdoc

@@ -42,9 +42,9 @@ import.
 To use the \l{Qt Quick} module, a QML document needs to
 import it. The import syntax looks like this:
 
-\qml
+\code
 import QtQuick 2.0
-\endqml
+\endcode
 
 The types and functionality that \l{Qt Quick} provides can now
 be used in the QML document!

doc/src/qmlapp/porting.qdoc

@@ -52,9 +52,9 @@ There are very few changes in the QML language that affect the porting of existi
 The \c QtQuick module has been updated to version 2.0. All QML applications should update their import
 statements to use the new version:
 
-\qml
+\code
 import QtQuick 2.0
-\endqml
+\endcode
 
 
 \section2 Property and Method Changes