PLT-3885 Add help text to System Console > Logs page (#6252)

* Add help text about user ID lookup

* logs banner

* Update logs.jsx

webapp/components/admin_console/logs.jsx

@@ -91,6 +91,14 @@ export default class Logs extends React.Component {
                         defaultMessage='Server Logs'
                     />
                 </h3>
+                <div className='banner'>
+                    <div className='banner__content'>
+                        <FormattedMessage
+                            id='admin.logs.bannerDesc'
+                            defaultMessage='To look up users by User ID, go to Reporting > Users and paste the ID into the search filter.'
+                        />
+                    </div>
+                </div>
                 <button
                     type='submit'
                     className='btn btn-primary'

webapp/i18n/en.json

@@ -532,6 +532,7 @@
   "admin.log.locationPlaceholder": "Enter your file location",
   "admin.log.locationTitle": "File Log Directory:",
   "admin.log.logSettings": "Log Settings",
+  "admin.logs.bannerDesc": "To look up users by User ID, go to Reporting > Users and paste the ID into the search filter.",
   "admin.logs.reload": "Reload",
   "admin.logs.title": "Server Logs",
   "admin.metrics.enableDescription": "When true, Mattermost will enable performance monitoring collection and profiling. Please see <a href=\"http://docs.mattermost.com/deployment/metrics.html\" target='_blank'>documentation</a> to learn more about configuring performance monitoring for Mattermost.",