build(aio): render type parameters of API function exports

Fixes #18123

aio/package.json

@@ -81,7 +81,7 @@
     "concurrently": "^3.4.0",
     "cross-spawn": "^5.1.0",
     "dgeni": "^0.4.7",
-    "dgeni-packages": "^0.20.0-rc.5",
+    "dgeni-packages": "^0.20.0-rc.6",
     "entities": "^1.1.1",
     "eslint": "^3.19.0",
     "eslint-plugin-jasmine": "^2.2.0",

aio/tools/transforms/templates/api/function.template.html

@@ -3,7 +3,7 @@
 
 {% block overview %}
 <code-example language="ts" hideCopy="true" class="no-box api-heading">
-function {$ doc.name $}{$ params.paramList(doc.parameters) $}
+function {$ doc.name $}{$ doc.typeParameters | escape $}{$ params.paramList(doc.parameters) $}
 {%- if doc.type %}: {$ doc.type | escape $}{% endif %};
 </code-example>
 {% endblock %}
@@ -13,7 +13,7 @@ function {$ doc.name $}{$ params.paramList(doc.parameters) $}
 {% if doc.overloads.length %}
   <h2>Overloads</h2>{% for overload in doc.overloads %}
   <code-example language="ts" hideCopy="true" class="no-box api-heading">
-  function {$ overload.name $}{$ params.paramList(overload.parameters) $}
+  function {$ overload.name $}{$ doc.typeParameters | escape $}{$ params.paramList(overload.parameters) $}
   {%- if overload.type %}: {$ overload.type | escape $}{% endif %};
   </code-example>
   <section class="description">

aio/yarn.lock

@@ -1904,9 +1904,9 @@ devtools-timeline-model@1.1.6:
     chrome-devtools-frontend "1.0.401423"
     resolve "1.1.7"
 
-dgeni-packages@^0.20.0-rc.5:
-  version "0.20.0-rc.5"
-  resolved "https://registry.yarnpkg.com/dgeni-packages/-/dgeni-packages-0.20.0-rc.5.tgz#09dd8134a3d79595578d6c0192ec0d82c78354be"
+dgeni-packages@^0.20.0-rc.6:
+  version "0.20.0-rc.6"
+  resolved "https://registry.yarnpkg.com/dgeni-packages/-/dgeni-packages-0.20.0-rc.6.tgz#d615e0631305dcf091386c802d0e424ef86206d2"
   dependencies:
     canonical-path "0.0.2"
     catharsis "^0.8.1"