Improve Chronoclust workflow

[ghar1821]

1. Create xml writer to write the input xml. The logic behind this is the common workflow. So user normally specify a folder where there are csv files (their data), do some manipulation, then do clustering. So if we can come up with a xml writer that writes the input xml after the user manipulate the data, it'll be nice.
2. Write better documentation for setting up anaconda and environment. Put more screenshot on the vignette.
3. Add demo dataset comprising different days and different samples/groups.

[ghar1821]

ChronoClust workflow has been massively streamlined such that it closely resembles the standard in Spectre i.e. attach the cluster id as a column to the data frame. Thus there is no need for 1.

A new function for setting up anaconda environment has also been created. Documentation on the wiki has also been updated. Thus step 2 is done.