Doc and script updated

README.md

@@ -96,7 +96,14 @@ $ ./getqwt.sh
 $ cd ~/qwt-6.1
 ```
 
-After that add environment variables to your ~/.bashrc.
+After that add environment variables to your ~/.bashrc. Open the file with a
+text editor (e.g., nano, gedit, kate, notepad++, subl, atom, ultraedit, emacs,
+vim, etc.).
+
+```bash
+$ nano ~/.bashrc
+```
+
 
 ```bash
 export LIBQWT_HOME=${HOME}/qwt-6.1/lib
@@ -104,8 +111,9 @@ export LIBQWT_HEADERS=${HOME}/qwt-6.1/src
 export LD_LIBRARY_PATH=${LD_LIBRARY_PATH:+${LD_LIBRARY_PATH}:}${LIBQWT_HOME}
 ```
 
-Remember to verify that the library and header files are located in paths you
-specify. You can use the **ls** command to accomplish that.
+Remember to verify that the library was created and the header files are
+located in the paths you specify. You can use the **ls** command to accomplish
+that.
 
 ```bash
 $ ls ${HOME}/qwt-6.1/lib
@@ -116,7 +124,7 @@ Further information about Qwt can be found [here](http://qwt.sourceforge.net/).
 
 To grant flexibility to the user the paths where to find some essential
 libraries and headers can be specified with environment variables. Make sure
-you have the environment variables below in your ~/.bashrc file.
+you have the environment variables below defined in your ~/.bashrc file.
 
 **Note that some of the variables are automatically generated by the scripts. If
 you install the libraries in custom paths in your system you have to adapt the