update: Added daily journal entries

* Implemented the functionality for adding daily journal notes. The
  general procedure geos as follows:

  1. The necessary directories/files are created.
  2. The default intro string gets written into the file
  3. The file is opened in the default text editor
update: Fixed the name of the note file

* Added the correct suffix and used TitleToFilename function to rewrite
  the title into the filename
update: Added file existence check

* Added check that prevents writing the default text into the same file
  again
janitoring: Name updates and traling spaces

* Updated every name to gonote

* Cleaned trailing spaces