Describe motivation in README (#192)

* docs: describe motivation in README

* Update README.md

Co-authored-by: Darius Dzien <[email protected]>

* tweaks

* tweaks again

* Update README.md

Co-authored-by: Darius Dzien <[email protected]>

* tweaks

Co-authored-by: Darius Dzien <[email protected]>

Author: bmish

README.md

@@ -5,6 +5,14 @@
 
 This plugin checks to ensure that dependencies are on consistent versions across a monorepo / yarn workspace. For example, every package in a workspace that has a dependency on `eslint` should specify the same version for it.
 
+## Motivation
+
+* **Supports a uniform developer experience.** Like shared code formatting standards, consistent dependency versions reduce friction and make it easier for developers to jump around and work across packages in a monorepo.
+* **Discourages piecemeal upgrades.** When possible, a dependency should be upgraded everywhere it exists in a monorepo at the same time. Upgrades are also simpler and easier to perform when fewer versions are present.
+* **Reduces unexpected behavior.** Having old versions present can lead to confusion, e.g., a bug present in some parts of a monorepo but not others, or uncertainty about which version wins out when served to the browser.
+* **Cuts down on bundle size.** Avoid serving excess dependency code to the browser.
+* **Saves disk space and installation time.** Faster local development and CI.
+
 ## Usage
 
 To install: