Importing multiple csv files and storing it into a list of data frames
importCsv function loads .csv file types in a selected directory to separate dataframes, and stores them as a list. Data frames can be accessed as list elements by using "listname$filename" or "listname".
the directory in which the files are stored. If path is not given, interactive dialog box will be used to select directory
a single list of dataframes containing all the files imported and stored as dataframes.