Add information for contributers

.github/CONTRIBUTING.md

+# Contributing to Rocket.Chat
+
+:+1::tada: First off, thanks for taking the time to contribute! :tada::+1:
+
+The following is a set of guidelines for contributing to Rocket.Chat and its packages, which are hosted in the [Rocket.Chat Organization](https://github.com/RocketChat) on GitHub.
+
+__Note:__ If there's a feature you'd like, there's a bug you'd like to fix, or you'd just like to get involved please raise an issue and start a conversation. We'll help as much as we can so you can get contributing - although we may not always be able to respond right away :)
+
+## Coding standards
+
+We are following / moving to [Google Java Style](https://google.github.io/styleguide/javaguide.html). There's a nice IntelliJ (and therefore Android Studio) [plugin](https://plugins.jetbrains.com/plugin/8527) for code formatting.
+
+We acknowledge all the code does not meet these standards but we are working to change this over time.
+
+### Syntax check
+
+Before submitting a PR you should get no errors on `checkstyle`.
+
+Just run:
+
+```
+./gradlew checkstyle
+```

.github/ISSUE_TEMPLATE.md

+Your Rocket.Chat.Android version: (make sure you are running the latest)
\ No newline at end of file

.github/PULL_REQUEST_TEMPLATE.md

+<!-- INSTRUCTION: Keep the line below to notify all core developers about this new PR -->
+@RocketChat/android
+
+<!-- INSTRUCTION: Inform the issue number that this PR closes, or remove the line below -->
+Closes #ISSUE_NUMBER
+
+<!-- INSTRUCTION: Tell us more about your PR with screen shots if you can -->
\ No newline at end of file

CODE_OF_CONDUCT.md

+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+nationality, personal appearance, race, religion, or sexual identity and
+orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting the project team at team@rocket.chat . The project team
+will review and investigate all complaints, and will respond in a way that it deems
+appropriate to the circumstances. The project team is obligated to maintain
+confidentiality with regard to the reporter of an incident.
+Further details of specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at [http://contributor-covenant.org/version/1/4][version]
+
+[homepage]: http://contributor-covenant.org
+[version]: http://contributor-covenant.org/version/1/4/
\ No newline at end of file

SECURITY.md

+# Reporting Security Issues
+
+Please report any security issues you discovered to security[at]rocket[dot]chat
+
+We will assess the risk, plus make a fix available before we create a GitHub issue.
+
+Thank you for your contribution.
\ No newline at end of file