Correct the headers and the doc

[amtoine]

As scripts have been renamed recently, the headers of the scripts and the mentions to the old file names are incorrect.

This issue proposes to correct the headers and to change the mentions to the old names to the new ones.

IMPLEMENTATION DETAILS: let's take the example of the battery script.

1. it has been renamed from ./scripts/battery.sh to ./scripts/a2n-s-battery -> change every occurence of battery.sh to a2n-s-battery. below is an extract of the diff:

   @@ -145,3 +146,3 @@ help () {
   #
   -  echo "battery.sh:"
   +  echo "a2n-s-battery:"
   echo "     a script to check the state of the battery and throw appropriate notifications."
   @@ -149,3 +150,3 @@ help () {
   echo "Usage:"
   -  echo "     battery.sh [-hcp]"
   +  echo "     a2n-s-battery [-hcp]"
   echo ""

2. correct the header with the following diff

   diff --git a/scripts/a2n-s-battery b/scripts/a2n-s-battery
   index 057d33e..3e92545 100755
   --- a/scripts/a2n-s-battery
   +++ b/scripts/a2n-s-battery
   @@ -3,27 +3,29 @@
   #      __ _|_  )_ _ ___ ___   personal page: https://a2n-s.github.io/
   #     / _` |/ /| ' \___(_-<   github   page: https://github.com/a2n-s
   #     \__,_/___|_||_|  /__/   my   dotfiles: https://github.com/a2n-s/dotfiles
   -#        _     __  _        __  _          _   _                     _
   -#       | |   / / | |__    / / | |__  __ _| |_| |_ ___ _ _ _  _   __| |_
   -#      _| |  / /  | '_ \  / /  | '_ \/ _` |  _|  _/ -_) '_| || |_(_-< ' \
   -#     (_)_| /_/   |_.__/ /_/   |_.__/\__,_|\__|\__\___|_|  \_, (_)__/_||_|
   -#                                                          |__/
   +#           ___                _          _   _
   +#      __ _|_  )_ _ ___ ______| |__  __ _| |_| |_ ___ _ _ _  _
   +#     / _` |/ /| ' \___(_-<___| '_ \/ _` |  _|  _/ -_) '_| || |
   +#     \__,_/___|_||_|  /__/   |_.__/\__,_|\__|\__\___|_|  \_, |
   +#                                                         |__/

[amtoine]

Also, the path to the LICENSE has to be changed from https://github.com/a2n-s/dotfiles/blob/main/LICENSE to https://github.com/a2n-s/scripts/blob/main/LICENSE.