docs: remove warning about pruned nodes

This removes a warning in the documentation saying that pruned nodes are
not supported. This is no longer the case as [pruning is supported since
0.13](https://github.com/lightningnetwork/lnd/pull/5154). So instead it
now says pruning is supported and notes the version and implications of
pruning.

docs/INSTALL.md

@@ -248,13 +248,8 @@ time of writing of this document, there are three available chain backends:
 `btcd`, `neutrino`, `bitcoind`. All including neutrino can run on mainnet with
 an out of the box `lnd` instance. We don't require `--txindex` when running
 with `bitcoind` or `btcd` but activating the `txindex` will generally make
-`lnd` run faster.
+`lnd` run faster. Note that since version 0.13 pruned nodes are supported
-
+although they cause performance penalty and higher network usage.
-**NOTE: WE DO NOT FULLY SUPPORT PRUNED OPERATING MODES FOR FULL NODES.** It's
-possible to run a node in a pruned mode and have it serve lnd, however one must
-take care to ensure that `lnd` has all blocks on disk since the birth of the
-wallet, and the age of the earliest channels (which were created around March
-2018).
 
 The set of arguments for each of the backend modes is as follows:
 

docs/release-notes/release-notes-0.14.0.md

@@ -16,6 +16,11 @@ addholdinvoice call](https://github.com/lightningnetwork/lnd/pull/5533).
 * [A new build target itest-race](https://github.com/lightningnetwork/lnd/pull/5542) 
   to help uncover undetected data races with our itests.
 
+# Documentation
+
+* [Outdated warning about unsupported pruning was replaced with clarification that LND **does**
+  support pruning](https://github.com/lightningnetwork/lnd/pull/5553)
+
 # Misc
 
 * The direct use of certain syscalls in packages such as `bbolt` or `lnd`'s own
@@ -45,4 +50,4 @@ to make LNDs payment throughput (and latency) with better when using etcd.
 # Contributors (Alphabetical Order)
 * ErikEk
 * Zero-1729
-* Oliver Gugger
+* Oliver Gugger