Update README

README.md

@@ -0,0 +1,56 @@
+# TLE Generator
+
+Custom TLE file generator.
+
+## Usage:
+
+`TLEGenerator [-i INPUT] [-o OUTPUT]`
+
+## Optional arguments:
+
+```
+  -i INPUT      Download TLE for the specified catalog numbers.
+  -o OUTPUT     Output file path.
+```
+
+## Configuration file (config.json)
+
+| Value | Default | Description |
+|-|-|-|
+| NoradUrl | https://celestrak.com/NORAD/elements/gp.php | NORAD API URL. |
+| Groups | weather, amateur | Groups to retrieve the TLE data. Consider add or remove groups to reduce the number of API requests and increase performace. |
+| SatellitesListPath | satellites.json | File containing the NORAD catalog numbers for the tracked satellites. Get more catalog numbers at https://www.celestrak.com/satcat/search.php |
+| OutputFilePath | custom_TLE.txt | Generated file. |
+| TempFolder | /tmp | Folder where downloaded files are stored. |
+| TempFilesDays | 1 | Number of days that the temporary files are valid before downloading them again. |
+
+
+## Examples:
+
+Generate a TLE file with the NORAD catalog numbers included in the file `satellites.txt`:
+
+```
+# ./TLEGenerator
+
+✓ Saved TLE for METEOR-M2 3 (57166)
+✓ Saved TLE for NOAA 15 (25338)
+✓ Saved TLE for NOAA 18 (28654)
+✓ Saved TLE for NOAA 19 (33591)
+✓ Saved TLE for ISS (ZARYA) (25544)
+TLEs retrieved: 5/5
+API requests: 2
+Output TLE file: /Users/ea7koo/Documents/TLEGenerator/custom_TLE.txt
+```
+
+Generate the TLE file `weather.txt` with the NORAD catalog numbers `25338`, `28654`, and `33591`:
+
+```
+# ./TLEGenerator -o weather.txt -i 25338,28654,33591
+
+✓ Saved TLE for NOAA 15 (25338)
+✓ Saved TLE for NOAA 18 (28654)
+✓ Saved TLE for NOAA 19 (33591)
+TLEs retrieved: 3/3
+API requests: 1
+Output TLE file: /Users/ea7koo/Documents/TLEGenerator/weather.txt
+```