doc: fix some signatures of .end() methods

In `.end()` methods, an optional `encoding` parameter makes sense
only if the `data` (`chunk`) parameter is provided.

PR-URL: #29615
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

Author: vsemozhetbyt

doc/api/http.md

@@ -1167,7 +1167,7 @@ added: v0.3.0
 
 See [`response.socket`][].
 
-### response.end([data][, encoding][, callback])
+### response.end([data[, encoding]][, callback])
 <!-- YAML
 added: v0.1.90
 changes:

doc/api/http2.md

@@ -3016,7 +3016,7 @@ added: v8.4.0
 
 See [`response.socket`][].
 
-#### response.end([data][, encoding][, callback])
+#### response.end([data[, encoding]][, callback])
 <!-- YAML
 added: v8.4.0
 changes:

doc/api/stream.md

@@ -391,7 +391,7 @@ added: v8.0.0
 
 Is `true` after [`writable.destroy()`][writable-destroy] has been called.
 
-##### writable.end([chunk][, encoding][, callback])
+##### writable.end([chunk[, encoding]][, callback])
 <!-- YAML
 added: v0.9.4
 changes: