Merge branch 'mh/gitcredentials-generate'

Doc update.

* mh/gitcredentials-generate:
  Docs: describe how a credential-generating helper works

Author: gitster

Documentation/gitcredentials.txt

@@ -62,7 +62,9 @@ for a password. It is generally configured by adding this to your config:
 
 Credential helpers, on the other hand, are external programs from which Git can
 request both usernames and passwords; they typically interface with secure
-storage provided by the OS or other programs.
+storage provided by the OS or other programs. Alternatively, a
+credential-generating helper might generate credentials for certain servers via
+some API.
 
 To use a helper, you must first select one to use. Git currently
 includes the following helpers:
@@ -288,8 +290,8 @@ For a `store` or `erase` operation, the helper's output is ignored.
 If a helper fails to perform the requested operation or needs to notify
 the user of a potential issue, it may write to stderr.
 
-If it does not support the requested operation (e.g., a read-only store),
-it should silently ignore the request.
+If it does not support the requested operation (e.g., a read-only store
+or generator), it should silently ignore the request.
 
 If a helper receives any other operation, it should silently ignore the
 request. This leaves room for future operations to be added (older