Read me updated

Author: sylvesterdas

README.md

@@ -1 +1,163 @@
-# caesar-cipher
+# GYKH - caesar-cipher
+
+> One of the simplest forms of encryption
+
+## Install
+
+```
+$ npm install --save @gykh/caesar-cipher
+```
+### or
+
+
+```
+$ npm i -S @gykh/caesar-cipher
+```
+
+## Usage
+
+Encrypt and decrypt string
+
+```js
+const { encryptString, decryptString } = require("@gykh/caesar-cipher");
+
+...
+
+const encrypted = encryptString(str, 3);
+
+const decrypted = decryptString(encrypted, 3);
+
+console.log(str === decrypted); // true
+```
+
+Encrypt and decrypt buffer
+
+```js
+const { encrypt, decrypt } = require("@gykh/caesar-cipher");
+const fs = require('fs');
+const { promisify } = require('util');
+const readFile = promisify(fs.readFile);
+
+...
+
+const encrypted = encrypt(await readFile(inputFile), 3);
+
+const decrypted = decrypt(encrypted, 3);
+
+console.log(buffer == decrypted); // true
+```
+
+Encrypt and decrypt streams
+
+```js
+const { EncryptTransform, DecryptTransform } = require("@gykh/caesar-cipher");
+const fs = require('fs'); 
+
+...
+
+const readStream = fs.createReadStream(inputFile);
+const writeStream = fs.createWriteStream(outputFile);
+
+const encryptTransform = new EncryptTransform(3);
+const decryptTransform = new DecryptTransform(3);
+
+const stream = readStream
+    .pipe(encryptTransform)
+    .pipe(decryptTransform)
+    .pipe(writeStream)
+
+stream.on("error", () => /* do something */);
+stream.on("finish", () => /* do something */);
+```
+
+## API
+
+### caesar-cipher
+
+### .encryptString(input, key)
+
+#### input
+
+Type: `string`<br/>
+Required
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+### .decryptString(input, key)
+
+#### input
+
+Type: `string`<br/>
+Required
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+### .encrypt(input, key)
+
+#### input
+
+Type: `Buffer`<br/>
+Required
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+### .decrypt(input, key)
+
+#### input
+
+Type: `Buffer`<br/>
+Required
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+### new EncryptTransform(key)
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+### new DecryptTransform(key)
+
+#### key
+
+Type: `number`<br/>
+Required
+
+key should be a number between 1-26
+
+## Understand Caesar Cipher
+
+> The Caesar cipher, also known as a shift cipher, is one of the simplest forms of encryption. It is a substitution cipher where each letter in the original message (called the plaintext) is replaced with a letter corresponding to a certain number of letters up or down in the alphabet. [Learn more](https://learncryptography.com/classical-encryption/caesar-cipher)
+
+## Developer
+
+- [Sylvester Das](https://www.sylvesterdas.com) 
+
+[!["Buy Me A Coffee"](https://www.buymeacoffee.com/assets/img/custom_images/black_img.png)](https://www.buymeacoffee.com/sylvester.das)
+
+## License
+
+MIT © 2021 [get-your-knowledge-here](./LICENSE)