ddns[46]_update documented argument names incorrect

src/bin/dhcp[46]/dhcp[46]_hooks.dox document arguments fwd_update, rev_update and ddns_params. Using these parameter names causes an exception to be thrown:

ERROR HOOKS_CALLOUT_EXCEPTION exception thrown by callout on hook ddns4_update registered by library with index 1 (callout address 0x7fff875b8ffc): unable to find argument with name fwd_update

The names for these arguments in the code are fwd-update, rev-update and ddns-param, i.e. the _'s should be -'s.

The following patch corrects the issue:

commit 67063ae09d2c1f924586404eea2fa85a328bccb5 (HEAD -> master)
Author: Quentin Armitage <quentin@armitage.org.uk>
Date:   Thu Feb 29 17:44:38 2024 +0000

    Fix documentation for ddns[46]_update hooks
    
    The documented argument names fwd_update, rev_update and ddns_params
    should be fwd-update, rev_update and ddns-params.
    
    Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>

diff --git a/src/bin/dhcp4/dhcp4_hooks.dox b/src/bin/dhcp4/dhcp4_hooks.dox
index ae6c903ff9..ed0620e035 100644
--- a/src/bin/dhcp4/dhcp4_hooks.dox
+++ b/src/bin/dhcp4/dhcp4_hooks.dox
@@ -260,9 +260,9 @@ called before "subnet4_select".
    - name: @b response4, type: isc::dhcp::Pkt4Ptr, direction: <b>in</b>
    - name: @b subnet4, type: isc::dhcp::Subnet4Ptr, direction: <b>in</b>
    - name: @b hostname, type: std::string, direction: <b>in/out</b>
-   - name: @b fwd_update, type: bool, direction: <b>in/out</b>
-   - name: @b rev_update, type: bool, direction: <b>in/out</b>
-   - name: @b ddns_params, type: isc::dhcp::DdnsParamsPtr, direction: <b>in</b>
+   - name: @b fwd-update, type: bool, direction: <b>in/out</b>
+   - name: @b rev-update, type: bool, direction: <b>in/out</b>
+   - name: @b ddns-params, type: isc::dhcp::DdnsParamsPtr, direction: <b>in</b>
 
  - @b Description: this callout is executed after the server has selected
    a lease and has formed a host name to associate with the lease and/or use
@@ -272,17 +272,17 @@ called before "subnet4_select".
    host name as well as whether or not forward and/or reverse updates are
    enabled.
 
-   Upon entry into the callout, the arguments <b>hostname</b>,<b>fwd_update</b>,
-   and <b>rev_update</b> have been set by the server based on the client packet,
+   Upon entry into the callout, the arguments <b>hostname</b>,<b>fwd-update</b>,
+   and <b>rev-update</b> have been set by the server based on the client packet,
    and various configuration values (e.g host reservations, DDNS behavioral
    parameters, etc).  Upon return from the callout, any changes to these
    values will be applied as follows:
    - If <b>hostname</b> has changed it will be used to update the outbound
    host name (option 12) if it exists, the output FQDN option (option 81)
    if it exists, and used as the FQDN sent in DNS updates
-   - Forward DNS update(s) will be done if <b>fwd_update</b> is true (and
+   - Forward DNS update(s) will be done if <b>fwd-update</b> is true (and
    <b>kea-dhcp-ddns</b> connectivity is enabled)
-   - Reverse DNS update(s) will be done if <b>rev_update</b> is true (and
+   - Reverse DNS update(s) will be done if <b>rev-update</b> is true (and
    <b>kea-dhcp-ddns</b> connectivity is enabled)
 
   - <b>Next step status</b>: Not applicable, its value will be ignored.

There appears to be no tests for the ddns[46]_update hooks. Should some be added?