Update release notes

export-noobs/00-release/files/release_notes.txt

@@ -1,5 +1,12 @@
 UNRELEASED:
-  *
+  * Raspberry Pi Configuration - screen blanking setting disabled if Xscreensaver is installed
+  * Bug fix - switch to turn off VNC server in Raspberry Pi Configuration has no effect
+  * Bug fix - fix %20 characters in file names
+  * Linux kernel 4.19.97
+  * Raspberry Pi firmware 2efcd0bb3848640e385c894b22551f0d32761bf8
+    - gencmd: Fix measure_clock name for CLOCK_OUTPUT_108
+    - mmal isp: Remote alignment requirements for RGB24 formats
+    - Add missing flags for VC_IMAGE_PROP_YUVUV_4K_CHROMA_ALIGN
 2020-02-05:
   * Version 3.2.6 of Thonny included - significant improvements in speed, particularly when debugging
   * Version 1.0.4 of Scratch 3 included - adds new "display stage" and "display sprite" blocks to SenseHAT extension, and loading of files from command line
@@ -23,8 +30,8 @@ UNRELEASED:
   * Ctrl-Alt-Del and Ctrl-Alt-End shortcuts added to open shutdown options box
   * Ctrl-Shift-Esc shortcut added to open task manager
   * Enabled NEON routines in OpenSSL
-  * Linux kernel 4.19.93
-  * Raspberry Pi firmware 67392a7a32bddad7f571047fccafca9eeb65d29c
+  * Linux kernel 4.19.97
+  * Raspberry Pi firmware 149cd7f0487e08e148efe604f8d4d359541cecf4
 2019-09-26:
   * rpi-eeprom included
     - This will automatically update the SPI EEPROM on the Raspberry Pi 4 to the latest stable version.