Clarify install instructions (#121)

* Clarify install instructions

* Correctly capitalise GOV.UK

Author: rossjones

lib/importer/assets/docs/start.html

@@ -67,7 +67,7 @@ <h1 class="govuk-heading-xl">Get started</h1>
             </p>
             <h2 class="govuk-heading-l">Installation</h2>
             <div data-static-only>
-                <p>Install the plugin by typing:</p>
+                <p>Open up your preferred command line, which you previously used to create a GOV.UK prototype, and type the following:</p>
                 <pre>npm install 'https://gitpkg.vercel.app/register-dynamics/data-import/lib/importer?main'</pre>
             </div>
             <p data-plugin-only class="govuk-body">
@@ -81,7 +81,7 @@ <h2 class="govuk-heading-l">Installation</h2>
             <h2 class="govuk-heading-l">Configuration</h2>
             <p>Finally, add some fields to <code>app/config.json</code> that the user will be asked for
                 when using the
-                "Identify columns" template:
+                "Identify columns" template. Replace the values "Code", "Name", and "Speciality" in the example below with your own fields:
             <pre>{
     "serviceName": "Your service name",
     "fields": [