Update README.md

Adding a description for the RSA keys, plus some corrections and improvements.

README.md

@@ -1,9 +1,9 @@
 # KRIS
-A PyQt5 python3 software that allow you to encrypt messages with secure ciphers. It implements RSA, AES and KRIS. KRIS encrypt the message with AES (which is faster than RSA), and then encrypt the used AES key with RSA (like PGP do).
+KRIS is a PyQt5 python3 software that allow you to encrypt messages with secure ciphers. It implements `RSA`, `AES` and `KRIS cipher`. `KRIS cipher` encrypt the message with AES (which is faster than RSA), and then encrypt the used AES key with RSA (as PGP do).
 
 The name come from the esperanto for cryptosystem, "kriptosistemo" ("KRIptoSistemo").
 
-You can generate your own RSA keys. They will be stored in `KRIS/Data/RSA_keys`. You can choose a password in the generate window, it will encrypted your key with AES-256-CBC.
+You can generate your own RSA keys. They will be stored in `KRIS/Data/RSA_keys` for portable mode (default), or in `~/.RSA_keys` (cf [below](https://github.com/lasercata/KRIS#rsa-keys) for details). You can choose a password in the generate window, it will encrypted your key with AES-256-CBC.
 
 ![Screenshot_2021 04 13_23h55 02](https://user-images.githubusercontent.com/67599917/114626132-cc3b3780-9ca2-11eb-9ecf-e6bebc825e7c.png)
 
@@ -19,7 +19,9 @@ Else you should be able to run the software by downloading the build version for
 
 
 ## Installing
+You can download directly the source code, or the last release, as you prefer. If you don't want to download Python3 and PyQt5, you can download the last release zip file that contain a build version for your OS (Windows or Linux).
 
+### Source code
 Download or clone the repository :
 
 ```bash
@@ -32,11 +34,23 @@ Make the launchers executable :
 chmod +x *.py
 ```
 
+### Release
+Go to the [last release](https://github.com/lasercata/KRIS/releases/latest), and download the zip file for your OS. Then unzip it.
+
 
 ## Running
 In the main directory, run `./KRIS_gui.py` to run the python script. Else you can run `./KRIS_gui` for Linux build, or `KRIS_gui.exe` for Windows build.
 
 
+## RSA keys
+You can manage RSA keys with the `Keys` menu. You can generate new ones, get info on them, export or import public keys, encrypt them, ...
+
+The default location for the keys is the folder `KRIS/Data/RSA_keys`. It is useful if you transport KRIS on a usb stick.
+But if you use it only on your computer, you can activate the `home` mode, meaning that the keys will be copied in the folder `~/.RSA_keys`. This is useful if you also use [Cracker](https://github.com/lasercata/Cracker) with `home` mode, or different versions of Cracker or KRIS (you won't have to copy the keys).
+
+The `home` mode can be activated in the settings (`Ctrl+R`).
+
+
 ## Authors
 
 * **Lasercata** - [Lasercata](https://github.com/lasercata)