docs: Adds React components naming conventions (#713)

Signed-off-by: Marcos Iglesias Valle <golodhros@gmail.com>

docs/react_naming_conventions.md

+# Amundsen's React Naming Conventions
+> A guide for naming React components on Amundsen
+
+React is not opinionated about the naming of our components. Having freedom is great, but this sometimes comes at the cost of lack of consistency on the API.
+
+To make sure Amundsen's React application is consistent and intuitive to use, we created this document that will describe the naming conventions for the React components.
+
+## Component Names
+
+### View Components
+
+We will follow this convention for naming our regular “view” components:
+
+_[Context]ComponentName[Type]_
+
+Where:
+*   Context - the parent component or high-level page
+*   ComponentName - what this component does. The responsibility of the component
+*   Type - the type of component. Usually they are views, but they could be a Form, a List, a Figure, an Illustration, a Container
+
+Examples:
+*   SideBar (root component)
+*   FooterSideBar (with context)
+*   SideBarForm (with component type)
+*   FooterSideBarForm (with all)
+
+
+### Custom Hook Components
+
+We will name custom hook components with a name starting with “use”, as mentioned on the [official docs](https://reactjs.org/docs/hooks-custom.html#extracting-a-custom-hook).
+
+
+### High-order Components
+
+We will name high order components (HOCs) using the “with” prefix. For example:
+
+*   withAuthentication
+*   withSubscription
+
+
+### Provider/Consumer Components
+
+Whenever we need to use the Provider/Consumer pattern and name the components, we will use the “Provider” and “Consumer” suffixes. For example:
+
+*   LoginProvider/LoginConsumer
+*   DataProvider/DataConsumer
+
+
+## Prop Names
+
+### Handler Functions
+
+We will use the “on” prefix for handler functions, optionally adding a “subject” word before the event. The schema would be “on[Subject]Event”, for example:
+
+*   onClick
+*   onItemClick
+*   onLogoHover
+*   onFormSubmit
+
+Internally, we will use the “handle” prefix for naming the handling functions, with an optional “subject” word in the middle. The schema would be then “handle[Subject]Event”, for example:
+
+*   handleClick
+*   handleButtonClick
+*   handleHeadingHover
+
+### Props by Type
+
+Props should be named to **describe** the component itself, and what it does, but not why it does it.
+
+*   Objects - Use a singular noun
+    *   item
+*   Arrays - Use a plural noun
+    *   items
+    *   users
+*   Numbers - Use a name with “num” prefix or with “count” or “index” suffix.
+    *   numItems
+    *   userCount
+    *   itemIndex
+*   Booleans - Use a “is”, “has”, or “can” prefix
+    *   “is” for visual variations
+        *   isVisible
+        *   isEnabled
+        *   isActive
+    *   “is” also for behavioral or conditional variations
+        *   isToggleable
+        *   isExpandable
+    *   “has” for toggling UI elements
+        *   hasCancelSection
+        *   hasHeader
+*   React Nodes - use “element” suffix
+    *   buttonElement
+    *   itemElement
+
+
+## Reference
+*   [How to name props for React components – David's Blog](https://dlinau.wordpress.com/2016/02/22/how-to-name-props-for-react-components/)
+*   [Handy Naming Conventions for Event Handler Functions & Props in React | by Juan Bernal | JavaScript In Plain English | Medium](https://medium.com/javascript-in-plain-english/handy-naming-conventions-for-event-handler-functions-props-in-react-fc1cbb791364)
+*   [https://medium.com/@wittydeveloper/react-components-naming-convention-%EF%B8%8F-b50303551505](https://medium.com/@wittydeveloper/react-components-naming-convention-%EF%B8%8F-b50303551505)
+*   [https://reactjs.org/docs/hooks-custom.html#extracting-a-custom-hook](https://reactjs.org/docs/hooks-custom.html#extracting-a-custom-hook) 
+*   [https://reactjs.org/docs/higher-order-components.html](https://reactjs.org/docs/higher-order-components.html)