specify delimiter for reading text files

[vedina]

i.e. RRUFF Raman files are .txt files with comma as delimiters https://rruff.info/zipped_data_files/raman/

[georgievgeorgi]

Comma separated .txt file may be read as csv.
Example:

import ramanchada2 as rc2
fn = 'Topaz__X050165.3__Raman__785__0__unoriented__Raman_Data_Processed__6699.txt'
spe = rc2.spectrum.from_local_file(fn, filetype='csv')
spe.plot()