Adding Contribution Guidelines for this repo

[vindard]

We are currently missing Contribution guidelines to help guide persons who may want to contribute to this repo.

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This Issue will serve to update the 'Contributing' section with a set of easy-to-follow guidelines that anyone can use to submit their own edit suggestions. It will also serve as our sample Issue for describing the process of making contribution suggestions. The edits to be made will be hashed out in the comments below and on the corresponding Pull Request that will be created from this.

For each Issue, a contributor on this repo will open a corresponding Pull Request and all the contributors will assist in making the necessary changes on that Pull Request to be merged.

We will also create guidelines for persons comfortable enough with using Github for themselves to fork this repo and create Pull Requests to submit their edits directly.

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Expected outcome: an edited 'Contributing' section that properly details the contribution process supported by links to both the sample Issue and sample Pull Request used to make the actual edits.

[vindard]

We can probably include a mini-section with tips on 'Issue' styling & structure, e.g. how I linked to the section I was referencing in the comment by using a combo of a screenshot and an anchor link.

We will also need to include an explanation of Markdown, little tips on using Markdown effectively and links to Markdown cheatsheets and samples, given that all the documents in this repo are written using Markdown.