v5.5.2

Updates v5.5.2:

1) Old style links in ino files have been renewed (links redirect to the same address in both cases).

2) Updated old reference to NewCurve and OldCurve in README.md file.

3) Cleaned extra spaces after the last line of the files.

4) Updated the beforeadme.txt file in the 4D_Slope folder.

5) Information file updated.

6) .gitattributes file added.

The libraries were divided into five different subgroups in v5.0.0:

1) MQ series gas sensor library

2) TGS series gas sensor library

3) MG811 gas sensor library

4) SP3S-AQ2 gas sensor library

5) Geiger Counter library

This library was customized for MQ series gas sensors!