feat: add package skeleton, constants.py and smoke tests

Task: MIL-001#3
Task: MIL-001#7

src/password_manager/__init__.py

@@ -0,0 +1,7 @@
+"""@brief A Tkinter password manager that stores entries in a JSON file.
+
+@file __init__.py
+@package password_manager
+"""
+
+__version__ = "0.1.0"

src/password_manager/constants.py

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+"""@brief Constants of the password manager.
+
+@file constants.py
+@details Every literal that more than one module needs, or that a reader may
+want to change, lives here and nowhere else.
+"""
+
+import string
+from pathlib import Path
+
+# Storage
+DATA_FILE_NAME = "data.json"  ##< Name of the JSON file that holds the entries.
+DATA_FILE_PATH = Path(
+    DATA_FILE_NAME
+)  ##< Default location, relative to the working directory.
+JSON_INDENT = 4  ##< Indentation of the written JSON, for readability.
+KEY_EMAIL = "email"  ##< JSON key of an entry's e-mail address.
+KEY_PASSWORD = "password"  ##< JSON key of an entry's password.
+
+# Password generator
+LETTERS = string.ascii_letters  ##< Letters a password may use.
+DIGITS = string.digits  ##< Digits a password may use.
+SYMBOLS = "!#$%&()*+"  ##< Symbols a password may use.
+MIN_LETTERS = 8  ##< Fewest letters in a generated password.
+MAX_LETTERS = 10  ##< Most letters in a generated password.
+MIN_SYMBOLS = 2  ##< Fewest symbols in a generated password.
+MAX_SYMBOLS = 4  ##< Most symbols in a generated password.
+MIN_DIGITS = 2  ##< Fewest digits in a generated password.
+MAX_DIGITS = 4  ##< Most digits in a generated password.
+
+# Window
+WINDOW_TITLE = "Password Manager"  ##< Title of the main window.
+WINDOW_PADDING = 50  ##< Padding around the window content, in pixels.
+LOGO_SIZE = 200  ##< Width and height of the logo canvas, in pixels.
+DEFAULT_EMAIL = "name@example.com"  ##< E-mail address the form starts with.
+ENTRY_WIDTH_WIDE = 35  ##< Width in characters of the e-mail and add fields.
+ENTRY_WIDTH_NARROW = 21  ##< Width in characters of the website and password fields.
+
+# Labels and messages
+LABEL_WEBSITE = "Website:"
+LABEL_EMAIL = "Email/Username:"
+LABEL_PASSWORD = "Password:"
+BUTTON_SEARCH = "Search"
+BUTTON_GENERATE = "Generate Password"
+BUTTON_ADD = "Add"
+TITLE_OOPS = "Oops"
+TITLE_SAVED = "Saved"
+TITLE_FOUND = "Found"
+MESSAGE_EMPTY_FIELDS = "Please don't leave any fields empty!"
+MESSAGE_NO_DATA_FILE = "No Data File Found."
+MESSAGE_NO_DETAILS = "No details for {website} exists."
+MESSAGE_CONFIRM_SAVE = (
+    "These are the details entered:\nEmail: {email}\n"
+    "Password: {password}\nIs it ok to save?"
+)
+MESSAGE_DETAILS = "Email: {email}\nPassword: {password}"