[feat/flask] Small fixes and maintenance

- Fixed encoding error when reading locale.ini
- Added redirect from "/" route to "/en" route
- Added ifmain to app.py to fix Flask console error
- Added .gitignore for Flask
- Added requirements.txt

app.py

@@ -1,13 +1,19 @@
-from flask import Flask, render_template, request, url_for
+from flask import Flask, render_template, request, url_for, redirect
 from datetime import date
 from configparser import ConfigParser
 
 locale = ConfigParser()
-locale.read('locale.ini')
+with open('locale.ini', encoding='utf-8') as f:
+    locale.read_file(f)
+
 app = Flask(__name__)
 
 print(locale)
 
+@app.route("/")
+def home():
+    return redirect(url_for("index", lang="en"))
+
 @app.route("/<lang>")
 def index(lang):
     return render_template(f'{lang}.html', locale=locale, lang=lang, year=date.today().year)  # TODO: Check for vulnerability
@@ -16,4 +22,5 @@ def index(lang):
 def download_page(lang):
     return render_template('tmpl/download.htm', locale=locale, lang=lang)
 
-app.run(host="0.0.0.0", debug=True)
+if __name__ == "__main__":
+    app.run(host="0.0.0.0", debug=True)