docs: minor update of style guidelines

Also added a reference to the contributor guidelines and code of conduct
to the README

.github/contributing.md

@@ -1,6 +1,5 @@
 # Contributing Guidelines
 
-
 <!-- vim-markdown-toc GFM -->
 
 * [Example Law: The Law of Leaky Abstractions](#example-law-the-law-of-leaky-abstractions)
@@ -25,6 +24,7 @@ Some other tips:
 - Be careful not to copy-and-paste content (unless it is explicitly quoted), as it might violate copyright.
 - Include hyperlinks to referenced material.
 - Do not advocate for the law, or aim to be opinionated on the correctness or incorrectness of the law, as this repository is simply the descriptions and links.
+- Avoid 'you' when writing. For example, prefer "This law suggests refactoring should be avoided when..." rather than "you should avoid refactoring when...". This keeps the style slightly more formal and avoids seeming like advocation of a law.
 
 An example law is shown below, which covers most of the key points:
 

README.md

@@ -60,6 +60,7 @@ Like this project? Please considering [Sponsoring Me](https://github.com/sponsor
     * [YAGNI](#yagni)
     * [The Fallacies of Distributed Computing](#the-fallacies-of-distributed-computing)
 * [Reading List](#reading-list)
+* [Contributing](#contributing)
 * [TODO](#todo)
 
 <!-- vim-markdown-toc -->
@@ -701,6 +702,12 @@ If you have found these concepts interesting, you may enjoy the following books.
 - [The Dilbert Principle - Scott Adams](https://www.goodreads.com/book/show/85574.The_Dilbert_Principle) - A comic look at corporate America, from the author who created the [Dilbert Principle](#the-dilbert-principle).
 - [The Peter Principle - Lawrence J. Peter](https://www.goodreads.com/book/show/890728.The_Peter_Principle) - Another comic look at the challenges of larger organisations and people management, the source of [The Peter Principle](#the-peter-principle).
 
+## Contributing
+
+Please do contribute! [Raise an issue](https://github.com/dwmkerr/hacker-laws/issues/new) if you'd like to suggest an addition or change, or [Open a pull request](https://github.com/dwmkerr/hacker-laws/compare) to propose your own changes.
+
+Please be sure to read the [Contributing Guidelines](./.github/contributing.md) for requirements on text, style and so on. Please be aware of the [Code of Conduct](./.github/CODE_OF_CONDUCT.md) when engaging in discussions on the project.
+
 ## TODO
 
 Hi! If you land here, you've clicked on a link to a topic I've not written up yet, sorry about this - this is work in progress!