Doc: Prepare for 14.0-beta2 release (#11988)

Co-authored-by: Charles Pigott <charlespigott@googlemail.com>
Co-authored-by: Michael Lutz <michi@icosahedron.de>

changelog.txt

@@ -1,3 +1,15 @@
+14.0-beta2 (2023-02-04)
+------------------------------------------------------------------------
+Change: [NewGRF] Improved support for redefining default cargo types (#11719)
+Fix #11982: Crash when trying to place signals on things other than plain rails (#11977)
+Fix #11975: Inconsistent behaviour when changing first AI company settings (#11976)
+Fix #11972: Year cut off in graph windows (#11974)
+Fix #11968: Crash when opening orders window of new vehicles (#11973)
+Fix #11966: Monospace text in windows may not have been fully scrollable (#11981)
+Fix #11802: Made determining water region edge traversability more robust (#11986)
+Fix: Second colour vehicle-type default liveries were not being updated (#11971)
+
+
 14.0-beta1 (2023-02-03)
 ------------------------------------------------------------------------
 Feature: Order option to unbunch vehicles at depot (#11945)