fix README

.gitignore

 etc/
 usr/
-README.txt

README.txt

+Remove Unused Ubuntu Kernel
+
+Purge unused Ubuntu kernels
+
+Setup
+
+I’ll wait for better days to come and create a proper release process.
+Meanwhile I use Git LFS to upload the package inside the deb/ directory.
+
+You can download the package and install it:
+
+    sudo dpkg -i ubuntu-kernel-cleanup_<VERSION>_all.deb
+
+if the dependencies are not met:
+
+    sudo apt -y -f install
+
+How it works
+
+Script usage
+
+you can run the script using --real-run to remove the packages or use
+--dry-run to show which package would have been removed.
+
+Example:
+
+    ubuntu-kernel-cleanup.py --real-run
+
+or
+
+    ubuntu-kernel-cleanup.py --dry-run
+
+Configuration file
+
+The script will look for its configuration file in the following
+locations:
+
+1.  /etc/ubuntu-kernel-cleanup.ini
+2.  $HOME/.ubuntu-kernel-cleanup.ini
+
+if both files are available, the 2nd one will win.
+
+The file content looks as following:
+
+    [ubuntu-kernel-cleanup]
+    # you can get a list package prefixes and suffixes using "apt-cache search"
+
+    # number of kernels packages to keep
+    count = 2
+
+    # prefix comes after the version number
+    kernel_prefixes = linux-tools, linux-headers, linux-modules, linux-modules-extra, linux-image, linux-image-unsigned
+
+    # suffix come before the version number
+    kernel_suffixes = generic, aws
+
+How the script removes the kernels
+
+1st case
+
+you have 4 kernels installed and you use (count = 1):
+
+-   kernel1: it’s old, it’s the running kernel and you cannot uninstall
+    this one
+-   kernel2: old, intermediate kernel version, it can be uninstalled
+-   kernel3: old, intermediate kernel version, it can be uninstalled
+-   kernel4: the latest, it is also the running kernel and it will be
+    kept
+
+the script will remove kernel2 and kernel3
+
+2nd case
+
+If the running kernel does not belong to the list of the latest kernels,
+obtained with the option “count”, then count + 1 will be kept.
+
+For instance, if you use count = 2 with the following kernels installed:
+
+-   kernel1: old, it can be uninstalled
+-   kernel2: old, intermediate, but running kernel and it will be kept
+-   kernel3: old, intermediate kernel version, it can be uninstalled
+-   kernel4: the latest, it will be kept
+-   kernel5: the latest, it will be kept
+
+the script will remove kernel1 and kernel3
+
+3rd case
+
+You reboot and you are running the latest kernel.
+
+If you use count = 2, 2 kernels will be kept:
+
+-   kernel1: old, it can be uninstalled
+-   kernel2: old, intermediate, it can be uninstalled
+-   kernel3: old, intermediate kernel version, it can be uninstalled
+-   kernel4: the latest, it will be kept
+-   kernel5: the latest, running kernel, it will be kept
+
+the script will remove kernel1, kernel2 and kernel3