add LICENSE and Improve README

LICENSE.md

@@ -0,0 +1,34 @@
+# LICENSE
+PORTAL--STILL ALIVE demo by LHF (BD4SUP)
+
+September 2021
+
+Runs with Python 3 on most terminals with an 80x24 characters area.
+
+This program was adjusted specifically for serial 
+terminal under Linux in this case, an Informer 213 @ 19200bps and Ubuntu 14.04)
+
+Feel free to do whatever you like with this code.
+
+Personnel credits come from this project: https://github.com/xBytez/aperturescience
+
+ASCII arts come from this project: https://sites.google.com/site/gaddc11/Stillalive.rar?attredirects=0&d=1
+
+ My blog: EE Archeology @ http://7400.me
+
+PORTAL--STILL ALIVE demo is licensed under
+# GPL-3.0
+ the Free Software Foundation, either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#  Legal statement
+The copyright for song (Still Alive) belongs to Jonathan Coulton and Valve Software
+Contact me if there's copyright violation and if deletion of the content is needed.

README.md

@@ -1,3 +1,5 @@
+# PORTAL--STILL ALIVE demo
+
 在终端上演示《传送门》片尾曲效果的 Python 脚本程序。
 
 ## 使用条件

still_alive_credit.py

@@ -11,7 +11,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
 #
-# The copyright for song <Still Alive> belongs to Jonathan Coulton and Valve Software
+# The copyright for song (Still Alive) belongs to Jonathan Coulton and Valve Software
 # Contact me if there's copyright violation and if deletion of the content is needed.
 #
 #