doc: document support IDA versions

Text taken from master (except the Python version).

capa/ida/plugin/README.md

@@ -34,12 +34,29 @@ For more information on the FLARE team's open-source framework, capa, check out
 
 ### Requirements
 
-capa explorer supports the following IDA setups:
+capa explorer supports Python 2.7 and 3.6+ and the following IDA Pro versions:
 
-* IDA Pro 7.4+ with Python 2.7 or Python 3.
+* IDA 7.4
+* IDA 7.5
+* IDA 7.6 (caveat below)
 
 If you encounter issues with your specific setup, please open a new [Issue](https://github.com/fireeye/capa/issues).
 
+#### IDA 7.6 caveat: IDA 7.6sp1 or patch required
+
+As described [here](https://www.hex-rays.com/blog/ida-7-6-empty-qtreeview-qtreewidget/):
+
+> A rather nasty issue evaded our testing and found its way into IDA 7.6: using the PyQt5 modules that are shipped with IDA, QTreeView (or QTreeWidget) instances will always fail to display contents.
+
+Therefore, in order to use capa under IDA 7.6 you need the [Service Pack 1 for IDA 7.6](https://www.hex-rays.com/products/ida/news/7_6sp1). Alternatively, you can download and install the fix corresponding to your IDA installation, replacing the original QtWidgets DLL with the one contained in the .zip file (links to Hex-Rays):
+
+
+  - Windows: [pyqt5_qtwidgets_win](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_win.zip)
+  - Linux: [pyqt5_qtwidgets_linux](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_linux.zip)
+  - MacOS (Intel): [pyqt5_qtwidgets_mac_x64](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_mac_x64.zip)
+  - MacOS (AppleSilicon): [pyqt5_qtwidgets_mac_arm](https://www.hex-rays.com/wp-content/uploads/2021/04/pyqt5_qtwidgets_mac_arm.zip)
+
+
 ### Supported File Types
 
 capa explorer is limited to the file types supported by capa, which include: