Minor copy edits to website (#616)

### Summary

- leverage -> use
- make descriptions use consistent language

ecosystem/html_templates/webpage.html.jinja

@@ -47,7 +47,7 @@
           alt="Qiskit Ecosystem logo"
         />
         <p class="title-description">
-          Explore projects and hardware providers that leverage the open-source
+          Explore projects and hardware providers that use the open-source
           Qiskit toolkit or are built on top of it.
         </p>
 
@@ -103,7 +103,7 @@
         Transpiler plugins
       </h2>
       <p>
-        Use these projects to compile and optimize your quantum circuits.
+        Compile and optimize your quantum circuits
       </p>
       <div class="cards cds--row">{{section_transpiler_plugin_cards}}</div>
 
@@ -168,8 +168,7 @@
         Application packages
       </h2>
       <p>
-        Explore packages that help apply quantum technology to real-world use
-        cases
+        Packages that help apply quantum technology to real-world use cases
       </p>
       <div class="cards cds--row">
         {{section_applications_cards}}