New js modules documentation added (#3736)

* New js modules documentation added
* Documentation: Spelling and formatting

Co-authored-by: ElectronicsInFocus <rnadyrshin@gmail.com>
Co-authored-by: あく <alleteam@gmail.com>

documentation/js/js_textbox.md

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+# js_textbox {#js_textbox}
+
+# Textbox module
+```js
+let textbox = require("textbox");
+```
+# Methods
+
+## setConfig
+Set focus and font for the textbox.
+
+### Parameters
+- focus: "start" to focus on the beginning of the text, or "end" to focus on the end of the text
+- font: "text" to use the default proportional font, or "hex" to use a monospaced font, which is convenient for aligned array output in HEX
+
+### Example
+```js
+textbox.setConfig("start", "text");
+textbox.addText("Hello world");
+textbox.show();
+```
+
+## addText
+Add text to the end of the textbox.
+
+### Parameters
+- text (string): The text to add to the end of the textbox
+
+### Example
+```js
+textbox.addText("New text 1\nNew text 2");
+```
+
+## clearText
+Clear the textbox.
+
+### Example
+```js
+textbox.clearText();
+```
+
+## isOpen
+Return true if the textbox is open.
+
+### Returns
+True if the textbox is open, false otherwise.
+
+### Example
+```js
+let isOpen = textbox.isOpen();
+```
+
+## show
+Show the textbox. You can add text to it using the `addText()` method before or after calling the `show()` method.
+
+### Example
+```js
+textbox.show();
+```
+
+## close
+Close the textbox.
+
+### Example
+```js
+if (textbox.isOpen()) {
+    textbox.close();
+}
+```