Update README to reflect current versions & requirements

Signed-off-by: alexanderharm <[email protected]>

README.md

@@ -132,12 +132,12 @@ Optional:
 - [ ] Git bash (it comes with Git):
       https://git-scm.com/download/win
 
-- [ ] Qt 5.12.9 (select in the wizard: MSVC 2017 64-bit AND 32-bit and all the "Qt ..." options, not required: Debug Info Files):
+- [ ] Qt 5.15.2 (select in the wizard: MSVC 2019 64-bit AND 32-bit and all the "Qt ..." options, not required: Debug Info Files):
       http://download.qt.io/official_releases/online_installers/qt-unified-windows-x86-online.exe
 
       Install to: C:\Qt
 
-  Note: MSVC 2017 is binary compatible with VS 2019, so don't be confused ;-)
+  Note: See `QT_PATH` in [](defaults.inc.bat) for currently used version. Then set: `QT_PATH=c:/Qt/5.15.2` (adjust version as needed) 
 
 - [ ] CMake 3.14.x (choose the ZIP version, extract and rename to: C:\Nextcloud\tools\cmake):
       https://cmake.org/download/
@@ -159,6 +159,9 @@ Optional:
           You may also use these libraries instead of the ones above but then you have to modify the paths in defaults.inc.bat
           and be sure to check for updates on a regular basis!
 
+- [ ] Inkscape (make sure to select option to add to `%PATH%` during installation):
+      https://inkscape.org/release/
+
 ## NSIS (Nullsoft Scriptable Install System)
 - Install NSIS: https://nsis.sourceforge.io/Download/
 
@@ -238,7 +241,7 @@ build the client at any time later:
 
 - To build Release, collect all files but build no installer, don't sign and don't upload:
   ```
-  BUILD_INSTALLER=0 USE_CODE_SIGNING=0 UPLOAD_BUILD=0 ./build.bat Release
+  BUILD_INSTALLER=0 USE_CODE_SIGNING=0 UPLOAD_BUILD=0 QT_PATH=c:/Qt/5.15.2 ./build.bat Release
   ```
 
 ## Explanation of the build scripts