docs: add basic usage guide

.vscode/settings.json

@@ -1,6 +1,7 @@
 {
   "cSpell.words": [
     "consolas",
+    "mdreport",
     "Twip"
   ]
 }

README.md

@@ -14,10 +14,70 @@ Writing characters, words and sentences is easy, but it is difficult to handle s
 
 The md-report helps you focus on the content rather than the style of your reports.
 
-## Usage
+## Basic Usage
 
+### Install Node.js v14+
 
+Just follow the [instruction on the official website](https://nodejs.org/en/download) to download and install Node.js.
+
+> For frontend developers, [nvm](https://github.com/nvm-sh/nvm) is a better choice.
+
+### Create Workspace Directory
+
+Create a folder that will contain your work of report and create a markdown file named `index.md` in the folder.
+
+Also create a `config.json` file to set the text in page headers.
+
+- `index.md`: Choose a template in (https://github.com/syy11cn/md-report/tree/main/templates) or write your own structure of reports.
+- `config.json`: Write the config file as follows (Remember to replace `<your_page_header_text>` with your own text). More configuration support and docs are on the way.
+
+```json
+{
+  "meta": {
+    "pageHeaderText": "<your_page_header_text>" // Will be placed in page header on even pages.
+  }
+}
+```
+
+### Run the Command
+
+- With `npx`:
+
+```bash
+cd <your_workspace_dir>
+npx @md-report/core
+```
+
+- Install the command globally:
+
+```bash
+npm i -g @md-report/core
+cd <your_workspace_dir>
+mdreport
+```
+
+By default, a `My Document.docx` file will be created in your workspace directory.
+
+### Custom Input and Output
+
+- To specify the input markdown file, use `-f` argument;
+- To specify the input config file, use `-c` argument;
+- To specify the filename of output document, use `-o` argument.
+
+### One More Step
+
+Because of the limit of dependency, the TOC is inserted but need to be manually updated.
+
+- After you get your `.docx` document, just open it, and check if there is any mistakes.
+- Then go to the first line on the first page.
+- Click the right button of your mouse, and select the `update field` item in the menu.
+
+Finally, you just need to combine your cover and your contents together. It's just a combination of two `.docx` files. You can find tons of utils and get your taste to solve it.
 
 ## Acknowledgement
 
 The idea comes from [slidev](https://github.com/slidevjs/slidev), a PowerPoint generator with markdown files.
+
+## License
+
+MIT &copy; 2022 Yiyang Sun