doc (publish): add info about stdin token to publish docs

Author: omskscream

src/doc/man/cargo-publish.md

@@ -30,6 +30,7 @@ following steps:
 
 This command requires you to be authenticated with either the `--token` option
 or using {{man "cargo-login" 1}}.
+Instead of `--token` option, _token_ value might also be provided via stdin.
 
 See [the reference](../reference/publishing.html) for more details about
 packaging and publishing.

src/doc/man/generated_txt/cargo-publish.txt

@@ -26,7 +26,8 @@ DESCRIPTION
           manually. This timeout does not affect the upload.
 
        This command requires you to be authenticated with either the --token
-       option or using cargo-login(1).
+       option or using cargo-login(1). Instead of --token option, token value
+       might also be provided via stdin.
 
        See the reference
        <https://doc.rust-lang.org/cargo/reference/publishing.html> for more

src/doc/src/commands/cargo-publish.md

@@ -26,6 +26,7 @@ following steps:
 
 This command requires you to be authenticated with either the `--token` option
 or using [cargo-login(1)](cargo-login.html).
+Instead of `--token` option, _token_ value might also be provided via stdin.
 
 See [the reference](../reference/publishing.html) for more details about
 packaging and publishing.

src/etc/man/cargo-publish.1

@@ -39,6 +39,7 @@ manually. This timeout does not affect the upload.
 .sp
 This command requires you to be authenticated with either the \fB\-\-token\fR option
 or using \fBcargo\-login\fR(1).
+Instead of \fB\-\-token\fR option, \fItoken\fR value might also be provided via stdin.
 .sp
 See \fIthe reference\fR <https://doc.rust\-lang.org/cargo/reference/publishing.html> for more details about
 packaging and publishing.