docs(added): add docs for addText, disconnect, addFeedLine methods

docs/printer/Printer.md

@@ -17,7 +17,7 @@ const printer = new Printer({
 
 ## Methods
 
-### [connect(`timeout: string`): `Promise<void>`](./connect.md)
+### [connect(`timeout?: string`): `Promise<void>`](./connect.md)
 
 Starts communication with the printer.
 
@@ -27,3 +27,33 @@ Starts communication with the printer.
 await printerInstance.connect();
 ```
 ---
+
+### [disconnect(): `Promise<void>`](./disconnect.md)
+
+Ends communication with the printer.
+
+#### Example
+
+```typescript
+await printerInstance.disconnect();
+```
+---
+### [addText(`text: string`): `Promise<void>`](./addText.md)
+
+Adds a character print command to the command buffer.
+
+#### Example
+
+```typescript
+await printerInstance.addText("Hello, World!");
+```
+---
+### [addFeedLine(`line?: number`): `Promise<void>`](./addFeedLine.md)
+
+Adds a paper-feed-by-line command to the command buffer.
+
+#### Example
+
+```typescript
+await printerInstance.addFeedLine(3);
+```

docs/printer/addFeedLine.md

@@ -0,0 +1,33 @@
+## addFeedLine
+
+Adds a paper-feed-by-line command to the command buffer.
+
+### Parameters
+
+#### line *(optional)*
+
+- `number`
+
+Specifies the paper feed amount (in lines).
+
+| **Value** |  **Description** | **Default** |
+| --- | --- | --- |
+| 0 to 255 | Paper feed amount (in lines) | 1 |
+
+### Returns
+
+`Promise<void>`
+
+### Errors
+
+| **Error status** | **Description** |
+| --- | --- |
+| ERR_PARAM | An invalid parameter was passed. |
+| ERR_TIMEOUT | Failed to communicate with the devices within the specified time. |
+| ERR_MEMORY | Necessary memory could not be allocated. |
+
+### Supplementary explanation
+
+
+- Calling this API causes the printer positioned at "the beginning of the line."
+

docs/printer/addText.md

@@ -0,0 +1,37 @@
+## addText
+
+Adds a character print command to the command buffer.
+
+### Parameters
+
+#### text
+
+- `string`
+
+Specifies the string to print.
+Use the following escape sequences for a horizontal tab and line feed.
+
+| **String** |  **Description** |
+| --- | --- |
+|`\t` | Horizontal tab (HT)|
+| `\n` | Line feed (LF)
+| `\\` | Backslash |
+
+### Returns
+
+`Promise<void>`
+
+### Errors
+
+| **Error status** | **Description** |
+| --- | --- |
+| ERR_PARAM | An invalid parameter was passed. |
+| ERR_TIMEOUT | Failed to communicate with the devices within the specified time. |
+| ERR_MEMORY | Necessary memory could not be allocated. |
+
+### Supplementary explanation
+
+
+- To print data other than text after printing text, feed a line or page.
+A line which does not end with a line feed will be discarded as unfixed data by the next [sendData](./sendData.md).
+

docs/printer/disconnect.md

@@ -0,0 +1,17 @@
+## disconnect
+
+Ends communication with the printer.
+
+### Returns
+
+`Promise<void>`
+
+### Errors
+
+| **Error status** | **Description** |
+| --- | --- |
+| ERR_MEMORY | Necessary memory could not be allocated. |
+| ERR_FAILURE | An unknown error occurred. |
+| ERR_PROCESSING | Could not run the process. |
+| ERR_DISCONNECT | Failed to disconnect the device. Tried to terminate communication with a printer during reconnection process. |
+