Update usage docs

Author: drpatelh

docs/usage.md

@@ -167,7 +167,7 @@ Please get in touch with us on the #rnaseq channel in the [nf-core Slack workspa
 The typical command for running the pipeline is as follows:
 
 ```bash
-nextflow run nf-core/rnaseq --input samplesheet.csv --outdir <OUTDIR> --genome GRCh37 -profile docker
+nextflow run nf-core/rnaseq --input ./samplesheet.csv --outdir ./results --genome GRCh37 -profile docker
 ```
 
 This will launch the pipeline with the `docker` configuration profile. See below for more information about profiles.
@@ -186,7 +186,8 @@ If you wish to repeatedly use the same parameters for multiple runs, rather than
 Pipeline settings can be provided in a `yaml` or `json` file via `-params-file <file>`.
 
 > ⚠️ Do not use `-c <file>` to specify parameters as this will result in errors. Custom config files specified with `-c` must only be used for [tuning process resource specifications](https://nf-co.re/docs/usage/configuration#tuning-workflow-resources), other infrastructural tweaks (such as output directories), or module arguments (args).
-> The above pipeline run specified with a params file in yaml format:
+
+The above pipeline run specified with a params file in yaml format:
 
 ```bash
 nextflow run nf-core/rnaseq -profile docker -params-file params.yaml
@@ -198,7 +199,6 @@ with `params.yaml` containing:
 input: './samplesheet.csv'
 outdir: './results/'
 genome: 'GRCh37'
-input: 'data'
 <...>
 ```