v3.12.0 (#4282)

* Use `parameterWithMeta` to get parameter data in <ParameterRow>

* Prefer specPath when fetching resolved subtrees in OperationContainer

* Add test for OAS3 callback rendering

* Remove debugger statement

* Pass base resolution URL directly to Swagger-Client subtree resolver

* Remove accidental comment

* Migrate additional options

* Don't default to empty Map when getting subtree

* fix(validateParam): check for ImList type before using count method

* Use `replaceState` to update `urls.primaryName`

This gives us the stateful URL we want, without:
(a) refreshing the page on update
(b) creating a long, useless history for the user
(c) implying that browser history is two-way bound
    to Swagger-UI (it isn't, we don't have a router)

* Add `fn.opsFilter` docs and internal API versioning note

* restrict `x-example` functionality to Swagger 2.0

* polish Authorize + Close buttons

* add tachyons; use it for padding the new Reset button

* v3.12.0

* rebuild dist

docs/customization/plug-points.md

@@ -0,0 +1,43 @@
+# Plug points
+
+Swagger-UI exposes most of its internal logic through the plugin system.
+
+Often, it is beneficial to override the core internals to achieve custom behavior.
+
+### Note: Semantic Versioning
+
+Swagger-UI's internal APIs are _not_ part of our public contract, which means that they can change without the major version changing.
+
+If your custom plugins wrap, extend, override, or consume any internal core APIs, we recommend specifying a specific minor version of Swagger-UI to use in your application, because they will _not_ change between patch versions.
+
+If you're installing Swagger-UI via NPM, for example, you can do this by using a tilde:
+
+```js
+{
+  "dependencies": {
+    "swagger-ui": "~3.11.0"
+  }
+}
+```
+
+### `fn.opsFilter`
+
+When using the `filter` option, tag names will be filtered by the user-provided value. If you'd like to customize this behavior, you can override the default `opsFilter` function.
+
+For example, you can implement a multiple-phrase filter:
+
+```js
+const MultiplePhraseFilterPlugin = function() {
+  return {
+    fn: {
+      opsFilter: (taggedOps, phrase) => {
+        const phrases = phrase.split(", ")
+
+        return taggedOps.filter((val, key) => {
+          return phrases.some(item => key.indexOf(item) > -1)
+        })
+      }
+    }
+  }
+}
+```