tidy file path in help text for invocation of docnn.json example

[mgoldey]

Motivation and Context

Help text in docs and for pytext executable had an incorrect file path for the example config file.

How Has This Been Tested

Tested via docker

docker run --rm -it --gpus all --entrypoint=/bin/bash --net host pytorch/pytorch:1.3-cuda10.1-cudnn7-runtime

export LC_ALL=C.UTF-8
export LANG=C.UTF-8

apt update && \
  apt install -y cmake protobuf-compiler libprotoc-dev ssh

git clone http://github.com/mgoldey/pytext.git

cd pytext
git checkout mgoldey/FixHelpText

source activation_venv && \
pip install torch pytest && \
./install_deps && \
python3 setup.py build && \
python3 setup.py install && \
python3 setup.py test

Output

----------------------------------------------------------------------
Ran 81 tests in 5.945s

OK

I've confirmed in that docker container that pytext --help gives

    pytext train < demo/configs/docnn.json

Types of changes

• Docs change / refactoring / dependency upgrade
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist

• My code follows the code style of this project.
  Enforced via black and isort invocations per CONTRIBUTING.md
• My change requires a change to the documentation.
  This is a change to the documentation
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have completed my CLA (see CONTRIBUTING)
  - [ ] I have added tests to cover my changes. N/A
  - [ ] All new and existing tests passed. N/A

[facebook-github-bot]

@rutyrinott has imported this pull request. If you are a Facebook employee, you can view this diff on Phabricator.

[facebook-github-bot]

@rutyrinott merged this pull request in 03b5779.