Complete user guide

docs/README.md

@@ -1,30 +1,127 @@
 # Devon User Guide
 
-// Update the title above to match the actual product name
+![Devon Chatbot Screenshot](Ui.png)
 
-// Product screenshot goes here
+Devon is an interactive chatbot designed to help you manage tasks 
+efficiently. It supports task creation, categorization, marking
+tasks as done, and more, all with an engaging personality.
 
-// Product intro goes here
+## Adding todos
+
+To add a todo task, simply provide the keyword `todo` followed by
+the task description. Devon will add this to the list.
+
+Example: `todo <task description>`
+
+Expected output:
+```
+Got it. I've added this task:
+    [T][] <task description>
+Now you have <task count> tasks in the list.
+```
 
 ## Adding deadlines
 
-// Describe the action and its outcome.
+To add a deadline task, simply provide the keyword `deadline`
+followed by the task description, the command `/by`, and the
+deadline date and time, in `YYYY-MM-DD HHmm` format.
+Devon will add this to the list.
+
+Example: `deadline <task description> /by <date and time>`
+
+Expected output:
+```
+Got it. I've added this task:
+    [D][] <task description> (by: <date and time>)
+Now you have <task count> tasks in the list.
+```
+
+## Adding events
+
+To add an event task, simply provide the keyword `event`
+followed by the task description, the command `/from`, the
+start date and time of the event in `YYYY-MM-DD HHmm`, the
+command `/to`, and the end date and time of the event in
+`YYYY-MM-DD HHmm` format. Devon will add this to the list.
+
+Example: `event <task description> /from <date and time> /to <date and time>`
+
+Expected output:
+```
+Got it. I've added this task:
+    [E][] <task description> (from: <date and time> to: <date and time>)
+Now you have <task count> tasks in the list.
+```
+
+## Delete task
 
-// Give examples of usage
+To delete a task, simply provide the keyword `delete` followed
+by the task number of the event. If an invalid number is provided,
+Devon will remind you that it is invalid.
 
-Example: `keyword (optional arguments)`
+Example: `delete 1`
 
-// A description of the expected outcome goes here
+Expected output:
+```
+Noted. I've removed this task:
+    [T][] <task description>
+Now you have <task count> tasks in the list.
+```
+
+## View all tasks
+
+To view all tasks, simply provide the keyword `list`, and Devon will
+display all tasks you currently have.
+
+Example: `list`
+
+Expected output:
+```
+Here are the tasks in your list:
+1. [T][] <task description>
+2. ...
+```
 
+## Mark task as done
+
+To mark a task as done, simply provide the keyword `mark` followed
+by the task number of the event. If an invalid number is provided,
+Devon will remind you that it is invalid.
+
+Example: `mark 1`
+
+Expected output:
 ```
-expected output
+Nice! I've marked this task as done:
+    [T][] <task description>
 ```
 
-## Feature ABC
+## Mark task as undone (a.k.a unmark task)
+
+To mark a task as undone, simply provide the keyword `unmark`
+followed by the task number of the event. If an invalid number
+is provided, Devon will remind you that it is invalid.
+
+Example: `unmark 1`
+
+Expected output:
+```
+OK, I've marked this task as not done yet:
+    [T][] <task description>
+```
 
-// Feature details
+## Shortform commands to create tasks
 
+The full-length keywords to create tasks are `todo`,
+`deadline` and `event`. However, the user can use the
+keywords `t`, `d` and `e` respectively to achieve the
+same results.
 
-## Feature XYZ
+Example (todo): `t <task description>`
+Example (deadline): `d <task description> /by <date and time>`
 
-// Feature details
+Expected output:
+Same as the output for
+- [Adding todos](#adding-todos)
+- [Adding deadlines](#adding-deadlines)
+- [Adding events](#adding-events)