Fix typos in PSLE certificate explanatory notes

[elliotwutingfeng]

Before

Candidates will be awarded one og the following grades:

After

Candidates will be awarded one of the following grades:

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name: Certificate Template Addition about: This is the workflow for requesting new certificate templates to be added to the OpenCerts repository title: "[New Template]" labels: new template assignees: ''

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Pull Request Guidelines for Adding Certificate Templates

This document is a work in progress but here are some basic checks. As these are only basic guidelines, meeting the below doesn't indicate there will be no issues with your pull request.

Pre-merge checks

• [x] Did not modify any files outside of your organisation's template folder (e.g package-lock.json or anything else)
• [x] Ensure that your code has been rebased on top of latest OpenCerts master
• [x] Linter issues resolved (Run npm run lint:fix to see issues)
• [x] npm run test passes
• [x] npm run test:integration passes
• [x] Travis Build passes

Certificate Template

• [x] No more than 5 templates or 25 added/modified files in the pull request
• [x] Ensure that your .opencert file's data complies with the intentions of the OpenCerts' schema - e.g recipient related information is inside the recipient object, etc.
• [x] Integration test for each template that checks that the correct rendering is done given a sample certificate
• [x] Sample certificate file included for each template, located alongside the integration test for each template
• [x] Sample certificates must obviously be a sample certificate
  • [x] Obviously fictitious name
  • [x] Obviously sample signatory images
• [x] No fixed-size raster images as part of certificate layout
• [x] Mobile responsive design
• [x] Date parsing should be localised to template author's timezone
• [x] Webpack chunking code is correct
  • [x] Has chunking code
  • [x] Same chunking code as the other certificates belonging to that institute
• [x] Certificate Store Addresses have been updated
  • [x] Template Whitelist
  • [x] Registry
• [x] Template should not be using resources(images etc.) on the website outside of their own folder (e.g institute logo shouldn't be used from /static because there's no guarantee it will not change)