Update docs, add changelog.

CHANGELOG.md

@@ -1,4 +1,7 @@
 # Unreleased
+  - Changes from 5.21.0
+    - Features:
+      - ADDED: new waypoints parameter to the `route` plugin, enabling silent waypoints [#5345](https://github.com/Project-OSRM/osrm-backend/pull/5345)
 
 # 5.21.0
   - Changes from 5.20.0

docs/http.md

@@ -195,6 +195,7 @@ In addition to the [general options](#general-options) the following options are
 |geometries  |`polyline` (default), `polyline6`, `geojson` |Returned route geometry format (influences overview and per step)              |
 |overview    |`simplified` (default), `full`, `false`      |Add overview geometry either full, simplified according to highest zoom level it could be display on, or not at all.|
 |continue\_straight |`default` (default), `true`, `false` |Forces the route to keep going straight at waypoints constraining uturns there even if it would be faster. Default value depends on the profile. |
+|waypoints   | `{index};{index};{index}...`                   |Treats input coordinates indicated by given indices as waypoints in returned Match object. Default is to treat all input coordinates as waypoints.    |
 
 \* Please note that even if alternative routes are requested, a result cannot be guaranteed.
 

docs/nodejs/api.md

@@ -57,6 +57,7 @@ Returns the fastest route between two or more coordinates while visiting the way
     -   `options.overview` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)** Add overview geometry either `full`, `simplified` according to highest zoom level it could be display on, or not at all (`false`). (optional, default `simplified`)
     -   `options.continue_straight` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?** Forces the route to keep going straight at waypoints and don't do a uturn even if it would be faster. Default value depends on the profile.
     -   `options.approaches` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Keep waypoints on curb side. Can be `null` (unrestricted, default) or `curb`.
+    -   `options.waypoints` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Indices to coordinates to treat as waypoints.  If not supplied, all coordinates are waypoints.  Must include first and last coordinate index.
                          `null`/`true`/`false`
 -   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)**
 
@@ -210,6 +211,7 @@ if they can not be matched successfully.
     -   `options.radiuses` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Standard deviation of GPS precision used for map matching. If applicable use GPS accuracy. Can be `null` for default value `5` meters or `double >= 0`.
     -   `options.gaps` **[String](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)?** Allows the input track splitting based on huge timestamp gaps between points. Either `split` or `ignore` (optional, default `split`).
     -   `options.tidy` **[Boolean](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)?** Allows the input track modification to obtain better matching quality for noisy tracks (optional, default `false`).
+    -   `options.waypoints` **[Array](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)?** Indices to coordinates to treat as waypoints.  If not supplied, all coordinates are waypoints.  Must include first and last coordinate index.
 -   `callback` **[Function](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/function)**
 
 **Examples**