Write a short summary of seqinspector in README.md

[Aratz]

seqinspector/README.md

Line 22 in 487f081

**nf-core/seqinspector** is a bioinformatics pipeline that ...

Complete this sentence with a 2-3 sentence summary of what types of data the pipeline ingests, a brief overview of the
major pipeline sections and the types of output it produces. You're giving an overview to someone new
to nf-core here, in 15-20 seconds. For an example, see https://github.com/nf-core/rnaseq/blob/master/README.md#introduction

[FranBonath]

handled in PR #111
The same PR also adds SeqFu to the documentation.