Fixes frappe#4

Add basic descriptions for each account in the default chart of accounts and move the "Chart of Accounts" section to the "Basics" section in the sidebar.

* **docs/miscellaneous/chart-of-accounts.md**
  - Add basic descriptions for each account in the default chart of accounts under a new section "Default Chart of Accounts".
  - Include descriptions for accounts under Assets, Liabilities, Equity, Income, and Expenses categories.

* **docs/.vitepress/sidebar.ts**
  - Move the "Chart of Accounts" section to the "Basics" section in the sidebar.