Website: Update margins on device-management and software-management pages (#45261)

Closes: https://github.com/fleetdm/fleet/issues/45204

Changes:
- Updated the margins in the `purpose="feature-with-text"` divs on the
/device-management and /software-management pages



<!-- end of auto-generated comment: release notes by coderabbit.ai -->

website/assets/styles/pages/device-management.less

@@ -503,14 +503,20 @@
     [purpose='feature-text'] {
       h2 {
         font-size: 28px;
-        margin-bottom: 32px;
+        margin-bottom: 0px;
       }
       h3 {
-        margin-bottom: 24px;
+        margin-bottom: 0px;
       }
       p {
         font-size: 16px;
-        margin-bottom: 32px;
+        margin-bottom: 0px;
+      }
+      [purpose='checklist'] {
+        .checklist();
+        p {
+          margin-bottom: 24px;
+        }
       }
     }
   }
@@ -520,9 +526,7 @@
     font-size: 12px;
     margin-bottom: 0px;
   }
-  [purpose='checklist'] {
-    .checklist();
-  }
+
   [purpose='feature-headline'] {
     max-width: 510px;
     margin-bottom: 80px;

website/assets/styles/pages/software-management.less

@@ -29,6 +29,7 @@
     font-size: 16px;
     line-height: @text-lineheight;
     color: @core-fleet-black-75;
+
   }
 
 
@@ -183,6 +184,9 @@
   [purpose='checklist'] {
     .checklist();
     margin-top: 8px;
+    p {
+      margin-bottom: 24px;
+    }
   }
   [purpose='feature-link'] {
     padding-top: 32px;
@@ -261,6 +265,15 @@
         font-size: 24px;
         font-weight: 800;
         line-height: @heading-lineheight; /* 120% */
+        margin-bottom: 0px;
+      }
+      p {
+        margin-bottom: 0px;
+      }
+      [purpose='checklist'] {
+        p {
+          margin-bottom: 24px;
+        }
       }
     }
   }