Update API includes to use English language paths (#1778)

Author: bjohansebas

en/3x/api.md

@@ -18,10 +18,10 @@ redirect_from: "/3x/api.html"
 
   <h1>3.x API</h1>
 
-  {% include api/{{ page.lang }}/3x/express.md %}
-  {% include api/{{ page.lang }}/3x/app.md %}
-  {% include api/{{ page.lang }}/3x/req.md %}
-  {% include api/{{ page.lang }}/3x/res.md %}
-  {% include api/{{ page.lang }}/3x/middleware.md %}
+  {% include api/en/3x/express.md %}
+  {% include api/en/3x/app.md %}
+  {% include api/en/3x/req.md %}
+  {% include api/en/3x/res.md %}
+  {% include api/en/3x/middleware.md %}
 
 </div>

en/4x/api.md

@@ -12,10 +12,10 @@ redirect_from: "/4x/api.html"
 
   {% include admonitions/note.html content="Express 4.0 requires Node.js 0.10 or higher." %}
 
-  {% include api/{{ page.lang }}/4x/express.md %}
-  {% include api/{{ page.lang }}/4x/app.md %}
-  {% include api/{{ page.lang }}/4x/req.md %}
-  {% include api/{{ page.lang }}/4x/res.md %}
-  {% include api/{{ page.lang }}/4x/router.md %}
+  {% include api/en/4x/express.md %}
+  {% include api/en/4x/app.md %}
+  {% include api/en/4x/req.md %}
+  {% include api/en/4x/res.md %}
+  {% include api/en/4x/router.md %}
 
 </div>

en/5x/api.md

@@ -12,10 +12,10 @@ redirect_from: "/5x/api.html"
 
   {% include admonitions/note.html content="Express 5.0 requires Node.js 18 or higher." %}
 
-  {% include api/{{ page.lang }}/5x/express.md %}
-  {% include api/{{ page.lang }}/5x/app.md %}
-  {% include api/{{ page.lang }}/5x/req.md %}
-  {% include api/{{ page.lang }}/5x/res.md %}
-  {% include api/{{ page.lang }}/5x/router.md %}
+  {% include api/en/5x/express.md %}
+  {% include api/en/5x/app.md %}
+  {% include api/en/5x/req.md %}
+  {% include api/en/5x/res.md %}
+  {% include api/en/5x/router.md %}
 
 </div>