v5.5.7

Updates v5.5.7:

1) The incorrect link citation in the library's article has been corrected.

2) The title of section 3, examined under the heading "What can be created?" in the README.md file, has been updated accordingly.

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!