docs: add release-notes

Author: MPins

docs/release-notes/release-notes-0.20.0.md

@@ -143,6 +143,11 @@ circuit. The indices are only available for forwarding events saved after v0.20.
   a whole. This new config prevents a single misbehaving peer from using up all
   the bandwidth.
 
+* [Add sat_per_kw option for more fine granular control of transaction 
+  fees](https://github.com/lightningnetwork/lnd/pull/10067). This option is added for the sendcoins, sendmany, openchannel, batchopenchannel,
+  closechannel, closeallchannels and wallet bumpfee commands. Also add
+  max_fee_per_kw for closechannel command.
+
 ## lncli Additions
 
 * [`lncli sendpayment` and `lncli queryroutes` now support the
@@ -154,6 +159,11 @@ circuit. The indices are only available for forwarding events saved after v0.20.
   [`--incoming_chan_ids` and `--outgoing_chan_ids`](https://github.com/lightningnetwork/lnd/pull/9356).
   These filters allows to query forwarding events for specific channels.
 
+* The [--sat_per_vbyte](https://github.com/lightningnetwork/lnd/pull/10067) 
+  option now supports fractional values (e.g. 1.05).
+  This option is added for the sendcoins, sendmany, openchannel,
+  batchopenchannel, closechannel, closeallchannels and wallet bumpfee commands. The max_fee_rate argument for closechannel also supports fractional values.
+
 # Improvements
 ## Functional Updates
 
@@ -256,6 +266,10 @@ reader of a payment request.
   v0.21.0. The `--tor.v2` configuration option is now
   [hidden](https://github.com/lightningnetwork/lnd/pull/10254).
 
+### ⚠️ **Warning:** The deprecated fee rate option --sat_per_byte will be removed in release version **0.21**
+
+  The following RPCs will be impacted: sendcoins, sendmany, openchannel, closechannel, closeallchannels and wallet bumpfee.
+
 # Technical and Architectural Updates
 ## BOLT Spec Updates