Doc: Cookie (#974)

* doc: cookie

* doc: cookie

* cookie: changes

docs/website/docs/v1.x/dsl/cookies/index.md

@@ -1 +1,110 @@
-# Work in progress
+# Cookie
+
+**ZIO HTTP** has special support for Cookie headers using the `Cookie` Domain to add and invalidate cookies. Adding a cookie will generate the correct [Set-Cookie](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie) headers
+
+## Create a Cookie
+
+`Cookie` can be created with params `name`, `content`, `expires`, `domain`, `path`, `isSecure`, `isHttpOnly`, `maxAge`, `sameSite` and `secret` according to HTTP [Set-Cookie](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie)  
+
+The below snippet creates a cookie `name` as `id` and `content` as `abc` with default params.
+```scala
+ val cookie: Cookie = Cookie("id", "abc")
+```
+### Update a Cookie
+
+- `withContent` updates the content of cookie
+```scala
+ val newCookie = cookie.withContent("def")
+```
+- `withExpiry` updates the expiration date of cookie
+```scala
+ val newCookie = cookie.withExpiry(Instant.MAX)
+```
+- `withMaxAge` updates the max-age of the cookie
+```scala
+ val newCookie = cookie.withMaxAge(5 days)
+```
+- `withDomain` updates the host to which the cookie will be sent
+```scala
+ val newCookie = cookie.withDomain("example.com")
+```
+- `withPath` updates the path of the cookie
+```scala
+ val newCookie = cookie.withPath(!! / "cookie")
+```
+- `withSecure` enables cookie only on https server 
+```scala
+ val newCookie = cookie.withSecure
+```
+- `withHttpOnly` forbids JavaScript from accessing the cookie
+```scala
+ val newCookie = cookie.withHttpOnly
+```
+- `withSameSite` updates whether or not a cookie is sent with cross-origin requests
+```scala
+ val newCookie = cookie.withSameSite(Instant.MAX)
+```
+
+## Reset a Cookie
+
+you can reset cookie params using:
+- `withoutSecure` resets `isSecure` to `false` in cookie
+- `withoutHttpOnly` resets `isHttpOnly` to `false` in cookie
+- `withoutExpiry` resets `expires` to `None`
+- `withoutDomain` resets `domain` to `None`
+- `withoutPath` resets `path` to `None`
+- `withoutMaxAge` resets `maxAge` to `None`
+- `withoutSameSite` resets `sameSite` to `None`
+
+## Sign a Cookie
+
+The cookies can be signed with a signature:
+
+ - Using `sign`
+ To sign a cookie, you can use `sign`
+```scala
+ val cookie = Cookie("key", "hello").withMaxAge(5 days)
+ val app = Http.collect[Request] { case Method.GET -> !! / "cookie" =>
+    Response.ok.addCookie(cookie.sign("secret"))
+  }
+```
+- Using `signCookies` middleware
+
+To sign all the cookies in your `HttpApp`, you can use `signCookies` middleware:
+```scala
+  private val cookie = Cookie("key", "hello").withMaxAge(5 days)
+  private val app = Http.collect[Request] {
+    case Method.GET -> !! / "cookie" => Response.ok.addCookie(cookie)
+    case Method.GET -> !! / "secure-cookie" => Response.ok.addCookie(cookie.withSecure)
+  }
+
+  // Run it like any simple app
+  override def run(args: List[String]): URIO[zio.ZEnv, ExitCode] =
+    Server.start(8090, app @@ signCookies("secret")).exitCode
+``` 
+
+## Adding Cookie in Response
+
+The cookies can be added in `Response` headers:
+```scala
+ val cookie1: Cookie = Cookie("id", "abc")
+ val res = Response.ok.addCookie(cookie1)
+```
+It updates the response header `Set-Cookie` as
+
+```Set-Cookie: <cookie-name>=<cookie-value>```
+
+## Getting Cookie from Request
+
+In HTTP requests, cookies are stored in the `cookie` header.
+`cookiesDecoded` can be used to get all the cookies in the request.
+
+```scala
+ private val app = Http.collect[Request] {
+    case req @  Method.GET -> !! / "cookie" =>
+      Response.text(req.cookiesDecoded.mkString(""))
+  }
+```
+
+
+