adding multiqc version 1.22.3

There's a new version of multiqc!

According to the release notes, https://github.com/MultiQC/MultiQC/releases, this version is mostly minor bug fixes.

All I did was copy the files from 1.22.2 and update the version ARG.

$ diff multiqc/1.22.2/Dockerfile multiqc/1.22.3/Dockerfile 
3c3
< ARG MULTIQC_VER="1.22.2"
---
> ARG MULTIQC_VER="1.22.3"

Pull Request (PR) checklist:

[x] Include a description of what is in this pull request in this message.
[x] The dockerfile successfully builds to a test target for the user creating the PR. (i.e. docker build --tag samtools:1.15test --target test docker-builds/samtools/1.15 )
[x] Directory structure as name of the tool in lower case with special characters removed with a subdirectory of the version number (i.e. spades/3.12.0/Dockerfile)
- [x] (optional) All test files are located in same directory as the Dockerfile (i.e. shigatyper/2.0.1/test.sh)
[x] Create a simple container-specific README.md in the same directory as the Dockerfile (i.e. spades/3.12.0/README.md)
- [x] If this README is longer than 30 lines, there is an explanation as to why more detail was needed
[x] Dockerfile includes the recommended LABELS
[x] Main README.md has been updated to include the tool and/or version of the dockerfile(s) in this PR
[x] Program_Licenses.md contains the tool(s) used in this PR and has been updated for any missing

StaPH-B / docker-builds