Align cells across feature matrix tables

Make it easier for a user to follow a single column across multiple
tables of the feature matrix. Since the style sets cells to 25% width,
which assumes a table that is four cells wide, use a `style` tag so the
style only applies to the tables in the `teleport-editions.mdx` guide.

Closes gravitational/docs-website#134

Author: ptgott

docs/pages/teleport-editions.mdx

@@ -25,6 +25,18 @@ below.
 For information on how Teleport calculates billing metrics for product usage,
 see [Usage and Billing](./usage-billing.mdx).
 
+{/*Since the feature matrix includes multiple tables, set a fixed cell width to
+ensure that all tables are aligned.*/} 
+<style dangerouslySetInnerHTML={{__html: `
+  table {
+    table-layout: fixed;
+  }
+
+  table td {
+    width: 25%;
+  }`}}
+/>
+
 ## Teleport Zero Trust Access
 
 Teleport Zero Trust Access provides engineers with least-privileged access to