fix: Added clarifications to the behaviour of plugin:install and plug…

…in:link (#47)

Previously was in #45

src/commands/plugins/install.ts

@@ -7,6 +7,10 @@ import Plugins from '../../plugins'
 export default class PluginsInstall extends Command {
   static description = `installs a plugin into the CLI
 Can be installed from npm or a git url.
+
+Installation of a user-installed plugin will override a core plugin.
+
+e.g. If you have a core plugin that has a 'hello' command, installing a user-installed plugin with a 'hello' command will override the core plugin implementation. This is useful if a user needs to update core plugin functionality in the CLI without the need to patch and update the whole CLI.
 `
   static usage = 'plugins:install PLUGIN...'
   static examples = [

src/commands/plugins/link.ts

@@ -5,7 +5,12 @@ import cli from 'cli-ux'
 import Plugins from '../../plugins'
 
 export default class PluginsLink extends Command {
-  static description = 'links a plugin into the CLI for development'
+  static description = `links a plugin into the CLI for development
+Installation of a linked plugin will override a user-installed or core plugin.
+
+e.g. If you have a user-installed or core plugin that has a 'hello' command, installing a linked plugin with a 'hello' command will override the user-installed or core plugin implementation. This is useful for development work.
+`
+
   static usage = 'plugins:link PLUGIN'
   static examples = ['$ <%= config.bin %> plugins:link <%- config.pjson.oclif.examplePlugin || "myplugin" %> ']
   static args = [{name: 'path', description: 'path to plugin', required: true, default: '.'}]