doc: make spelling of behavior consistent

doc/api/crypto.md

@@ -1901,7 +1901,7 @@ the `crypto`, `tls`, and `https` modules and are generally specific to OpenSSL.
   <tr>
     <td><code>SSL_OP_CIPHER_SERVER_PREFERENCE</code></td>
     <td>Attempts to use the server's preferences instead of the client's when
-    selecting a cipher. Behaviour depends on protocol version. See
+    selecting a cipher. Behavior depends on protocol version. See
     https://www.openssl.org/docs/man1.0.2/ssl/SSL_CTX_set_options.html.</td>
   </tr>
   <tr>

doc/api/process.md

@@ -1635,7 +1635,7 @@ important ways:
    - TTYs (Terminals): *asynchronous* on Windows, *synchronous* on Unix
    - Pipes (and sockets): *synchronous* on Windows, *asynchronous* on Unix
 
-These behaviours are partly for historical reasons, as changing them would
+These behaviors are partly for historical reasons, as changing them would
 create backwards incompatibility, but they are also expected by some users.
 
 Synchronous writes avoid problems such as output written with `console.log()` or

doc/api/tls.md

@@ -982,7 +982,7 @@ changes:
     `"SSLv23_method"`. The possible values are listed as [SSL_METHODS][], use
     the function names as strings. For example, `"SSLv3_method"` to force SSL
     version 3.
-  * `secureOptions` {number} Optionally affect the OpenSSL protocol behaviour,
+  * `secureOptions` {number} Optionally affect the OpenSSL protocol behavior,
     which is not usually necessary. This should be used carefully if at all!
     Value is a numeric bitmask of the `SSL_OP_*` options from
     [OpenSSL Options][].

doc/api/util.md

@@ -443,7 +443,7 @@ will return its value, see [Custom promisified functions][].
 
 `promisify()` assumes that `original` is a function taking a callback as its
 final argument in all cases, and the returned function will result in undefined
-behaviour if it does not.
+behavior if it does not.
 
 ### Custom promisified functions