Fortsa first pre-release v0.0.1-alpha

After half a month of work, the first alpha version of Fortsa can now be released. It has completed the following tasks:

1. The main time series analysis test function of CTSA is converted to the Fortran interface version of Fortsa;
2. Lay the foundation so that we can gradually improve the interface of Fortsa.

Potential risks:

1. Only a certain part of the function interface has been tested, so if it needs to be applied to actual production work, it also needs to be customized by the user;
2. Fortsa only has a double-precision version.