[BUG] Error when tagging Sherpa due to spaCy trained pipeline for English not being installed

[artificialfintelligence]

Describe the bug
Manual installation instructions and Dockerfile are missing a newly required step: Downloading the spaCy trained pipeline for English.

To Reproduce

1. Perform a fresh installation of Sherpa following the directions here or a fresh redeployment of the docker container.
2. When you tag the Sherpa slack bot, it fails with the following error message in the console:

OSError: [E050] Can't find model 'en_core_web_sm'. It doesn't seem to be a Python package or a valid path to a data directory.

Also in Slack, you get the following error:

Additional context
The culprit is PR #273, specifically this commit.
It is easily fixed by performing the following command (to be added to the manual installation instructions, as well as, more importantly, the Dockerfile):

python -m spacy download en_core_web_sm

[artificialfintelligence]

@20001LastOrder I ran this by @Eyobyb and created a PR with the fix

[20001LastOrder]

Fixed by #333