Feat: add contribution guidelines

CONTRIBUTING.md

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+# Contributing guidelines
+
+## Before contributing
+
+Welcome to [TheAlgorithms/TypeScript](https://github.com/TheAlgorithms/TypeScript)! Before sending your pull requests,
+make sure that you **read the whole guidelines**. If you have any doubt on the contributing guide, please feel free to
+[state it clearly in an issue](https://github.com/TheAlgorithms/TypeScript/issues/new) or on our [**Discord server**](https://discord.gg/c7MnfGFGa6).
+
+## Contributing
+
+### Contributor
+
+We are very happy that you consider implementing algorithms and data structures for others! This repository is
+referenced and used by learners from around the globe. Being one of our contributors, you agree and confirm that:
+
+- You did your work - plagiarism is not allowed.
+  - Any plagiarized work will not be merged.
+- Your work will be distributed under [MIT License](LICENSE) once your pull request is merged.
+- Your submitted work must fulfill our styles and standards.
+
+**New implementations** are welcome! For example, new solutions to a problem, different representations of a graph data
+structure, or algorithm designs with different complexity.
+
+**Improving comments** and **writing proper tests** are also highly welcome.
+
+### Contribution
+
+We appreciate any contribution, from fixing grammar mistakes to implementing complex algorithms. Please read this
+section if you are contributing to your work.
+
+If you submit a pull request that resolves an open issue, please help us to keep our issue list small by adding
+`closes: #{$ISSUE_NO}` to your commit message. GitHub will use this tag to auto-close the issue if your PR is merged.
+
+#### What is an Algorithm?
+
+An Algorithm is one or more functions (or classes) that:
+
+- take one or more inputs.
+- perform some internal calculations or data manipulations.
+- return one or more outputs.
+- have minimal side effects.
+
+Algorithms should be packaged in a way that would make it easy for readers to put them into larger programs.
+
+Algorithms should:
+
+- have intuitive class and function names that make their purpose clear to readers.
+- use TypScript naming conventions and intuitive variable names to ease comprehension.
+- be flexible to take different input values.
+- raise TypeScript exceptions (RangeError, etc.) on erroneous input values.
+
+Algorithms in this repo should not be how-to examples for existing TypeScript packages. Instead, they should perform
+internal calculations or manipulations to convert input values into different output values. Those calculations or
+manipulations can use data types, classes, or functions of existing TypeScript packages but each algorithm in this repo
+should add unique value.
+
+#### File Naming Convention
+
+- Filenames should use the UpperCamelCase (PascalCase) style.
+- There should be no spaces in filenames.
+- **Example:** `UserProfile.ts` is allowed. Do not use `userprofile.ts`, `Userprofile.ts`, `user-Profile.ts`, `userProfile.ts`; these methods are discouraged.
+
+#### Commit Messages Formatting
+
+- Prefer to use the following format: `<type>: <short summary>`. If necessary, put any extra information in the description.
+- Commit types include (but are not limited to): 
+  - **docs**: Documentantion only changes
+  - **feat**: A new feature
+  - **fix**: A bug fix
+  - **chore**: Miscellaneous stuff that does not match any of the above
+
+- **Examples**: 
+  - `feat: add quicksort algorithm`
+  - `chore: fix spelling`
+  - `fix: improper error message`
+  -  `docs: add contributing guidelines`
+
+#### Module System
+
+We use the [ES Module](https://hacks.mozilla.org/2018/03/es-modules-a-cartoon-deep-dive/) system, which bring an official, standardized module system to JavaScript.
+
+It roughly means you will need to use `export` and `import` statements instead of `module.exports` and `require()`.
+
+#### Coding Style
+
+To maximize the readability and correctness of our code, we require that new submissions follow the
+[TypeScript Standard Style](https://github.com/standard/ts-standard).
+
+In order to apply the coding style (where it can be done automatically). If an error is shown, please figure out what's
+wrong, fix it and run standard again.
+
+A few (but not all) of the things to keep in mind:
+
+- Use camelCase with the leading character as lowercase for identifier names (variables and functions).
+- Names start with a letter.
+- Follow code indentation: Always use 2 spaces for indentation of code blocks.
+
+```ts
+function sum(arr: number[]): number {
+  let total = 0;
+  for (let i = 0; i < arr.length; i++) {
+    total += arr[i];
+  }
+  return total;
+}
+```
+
+- Avoid using global variables and avoid `==`.
+- Please use `let` over `var`.
+- Please refrain from using `console.log` or any other console methods.
+- **Absolutely** don't use `alert`.
+- We strongly recommend the use of ECMAScript 6.
+- Avoid the use of `any` type. Create an interface/class instead.
+- Don't prefix Interfaces with `I`.
+- Prefer not to use `null` nor `undefined` for explicit unavailability. 
+
+```ts
+// BAD
+let foo = { x: 123, y: undefined };
+
+// GOOD
+let foo: { x: number, y?: number } = { x:123 };
+```
+- Annotate arrays as `foos: Foo[]` instead of `foos: Array<Foo>`.
+- Avoid importing external libraries for basic algorithms. Only use those libraries for complicated algorithms.
+- Most importantly:
+  - **Be consistent in the use of these guidelines when submitting.**
+  - Happy coding!
+
+Written by [**@gefgu**](https://github.com/gefgu) and community, September 2022.