Modify release notes for PR 3137

We will not support accepting V2 channels in the v0.1 release, but
we do need to document the API change for push_msats -> channel_negotiation_type.

Author: dunxen

pending_changelog/3137-accept-dual-funding-without-contributing.txt

@@ -1,4 +1,4 @@
-# API Updates
+# API Updates (0.2)
  * Accepting dual-funded (V2 establishment) channels (without contibuting) is now supported (#3137).
    Some particulars to be aware of for this feature:
    * Creating dual-funded channels is not yet supported.

pending_changelog/3137-channel-negotiation-type.txt

@@ -0,0 +1,7 @@
+# API Updates
+ * `Event::OpenChannelRequest::push_msat` has been replaced by the field `channel_negotiation_type` to
+   differentiate between an inbound request for a dual-funded (V2) or non-dual-funded (V1) channel to be
+   opened, with value being either of the enum variants `InboundChannelFunds::DualFunded` and
+   `InboundChannelFunds::PushMsat(u64)` corresponding to V2 and V1 channel open requests respectively.
+   This is in preparation for supporting accepting dual-funded channels, which will be available in a later release.
+