Merge pull request #890 from nf-core/readme-admonitions

Fancy GitHub blockquote admonitions

Author: drpatelh

README.md

@@ -28,7 +28,8 @@ You can find numerous talks on the [nf-core events page](https://nf-co.re/events
 
 ![nf-core/rnaseq metro map](docs/images/nf-core-rnaseq_metro_map_grey.png)
 
-The SRA download functionality has been removed from the pipeline (`>=3.2`) and ported to an independent workflow called [nf-core/fetchngs](https://nf-co.re/fetchngs). You can provide `--nf_core_pipeline rnaseq` when running nf-core/fetchngs to download and auto-create a samplesheet containing publicly available samples that can be accepted directly as input by this pipeline.
+> **Note**
+> The SRA download functionality has been removed from the pipeline (`>=3.2`) and ported to an independent workflow called [nf-core/fetchngs](https://nf-co.re/fetchngs). You can provide `--nf_core_pipeline rnaseq` when running nf-core/fetchngs to download and auto-create a samplesheet containing publicly available samples that can be accepted directly as input by this pipeline.
 
 1. Merge re-sequenced FastQ files ([`cat`](http://www.linfo.org/cat.html))
 2. Read QC ([`FastQC`](https://www.bioinformatics.babraham.ac.uk/projects/fastqc/))
@@ -54,7 +55,8 @@ The SRA download functionality has been removed from the pipeline (`>=3.2`) and
 14. Pseudo-alignment and quantification ([`Salmon`](https://combine-lab.github.io/salmon/); _optional_)
 15. Present QC for raw read, alignment, gene biotype, sample similarity, and strand-specificity checks ([`MultiQC`](http://multiqc.info/), [`R`](https://www.r-project.org/))
 
-> - **NB:** Quantification isn't performed if using `--aligner hisat2` due to the lack of an appropriate option to calculate accurate expression estimates from HISAT2 derived genomic alignments. However, you can use this route if you have a preference for the alignment, QC and other types of downstream analysis compatible with the output of HISAT2.
+> **Warning**
+> Quantification isn't performed if using `--aligner hisat2` due to the lack of an appropriate option to calculate accurate expression estimates from HISAT2 derived genomic alignments. However, you can use this route if you have a preference for the alignment, QC and other types of downstream analysis compatible with the output of HISAT2.
 
 ## Quick Start