Update extensions docs and add resources

website/usage/_data.json

@@ -183,6 +183,7 @@
         "teaser": "Libraries, demos, books, courses and research systems featuring spaCy.",
         "menu": {
             "Third-party libraries": "libraries",
+            "Extensions": "extensions",
             "Demos & Visualizations": "demos",
             "Books & Courses": "books",
             "Jupyter Notebooks": "notebooks",

website/usage/_processing-pipelines/_extensions.jade

@@ -4,7 +4,8 @@ p
     |  We're very excited about all the new possibilities for community
     |  extensions and plugins in spaCy v2.0, and we can't wait to see what
     |  you build with it! To get you started, here are a few tips, tricks and
-    |  best practices:
+    |  best practices. For examples of other spaCy extensions, see the
+    |  #[+a("/usage/resources#extensions") resources].
 
 +list
     +item
@@ -104,7 +105,7 @@ p
         |  #[+a("https://pypi.python.org") PyPi]. If you're sharing your code on
         |  GitHub, don't forget to tag it
         |  with #[+a("https://github.com/search?q=topic%3Aspacy") #[code spacy]]
-        |  and #[+a("https://github.com/search?q=topic%3Aspacy-pipeline") #[code spacy-pipeline]]
+        |  and #[+a("https://github.com/search?q=topic%3Aspacy-extensions") #[code spacy-extensions]]
         |  to help people find it. If you post it on Twitter, feel free to tag
         |  #[+a("https://twitter.com/" + SOCIAL.twitter) @#{SOCIAL.twitter}]
         |  so we can check it out.

website/usage/resources.jade

@@ -41,6 +41,23 @@ include ../_includes/_mixins
     .u-text-right
         +button("https://github.com/search?o=desc&q=spacy&s=stars&type=Repositories&utf8=%E2%9C%93", false, "primary", "small") See more projects on GitHub
 
++section("extensions")
+    +h(2, "extensions") Extensions & Pipeline Components
+
+    p
+        |  This section lists spaCy extensions and components you can plug into
+        |  your processing pipeline. For more details, see the docs on
+        |  #[+a("/usage/processing-pipelines#custom-components") custom components]
+        |  and #[+a("/usage/processing-pipelines#extensions") extensions].
+
+    +grid
+        +card("spacymoji", "https://github.com/ines/spacymoji", "Ines Montani", "github")
+            |  Pipeline component for emoji handling and adding emoji meta data
+            |  to #[code Doc], #[code Token] and #[code Span] attributes.
+
+    .u-text-right
+        +button("https://github.com/search?o=desc&q=spacy-extensions&s=stars&type=Repositories&utf8=%E2%9C%93", false, "primary", "small") See more extensions on GitHub
+
 +section("demos")
     +h(2, "demos") Demos & Visualizations