Doc: edit texteditor plugin API docs

Fix grammar and style issues and punctuation.
Use the \a command instead of \param (not a QDoc command).

Change-Id: Ib048f0219a2c857e5fc3fcd858afbcbd58819193
Reviewed-by: David Schulz <david.schulz@digia.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@digia.com>

src/plugins/texteditor/basetextdocument.cpp

@@ -208,10 +208,10 @@ ITextMarkable *BaseTextDocument::documentMarker() const
 }
 
 /*!
- * \brief Saves the document to the specified file.
- * \param errorString output parameter, contains error reason.
- * \param autoSave signalise that this function was called by the automatic save routine.
- * If autosave is true, the cursor will be restored and some signals suppressed
+ * Saves the document to the file specified by \a fileName. If errors occur,
+ * \a errorString contains their cause.
+ * \a autoSave returns whether this function was called by the automatic save routine.
+ * If \a autoSave is true, the cursor will be restored and some signals suppressed
  * and we do not clean up the text file (cleanWhitespace(), ensureFinalNewLine()).
  */
 bool BaseTextDocument::save(QString *errorString, const QString &fileName, bool autoSave)

src/plugins/texteditor/codeassist/iassistprovider.cpp

@@ -52,7 +52,7 @@ using namespace TextEditor;
 /*!
     \fn bool TextEditor::IAssistProvider::supportsEditor(const QString &editorId) const
 
-    Returns whether this provider supports the editor which has the give \a editorId.
+    Returns whether this provider supports the editor which has the \a editorId.
 */
 
 /*!

src/plugins/texteditor/syntaxhighlighter.cpp

@@ -347,7 +347,7 @@ SyntaxHighlighter::SyntaxHighlighter(QTextEdit *parent)
 }
 
 /*!
-    Destructor. Uninstalls this syntax highlighter from the text document.
+    Destructor that uninstalls this syntax highlighter from the text document.
 */
 SyntaxHighlighter::~SyntaxHighlighter()
 {