Add clipboard.md & security.png, update relevant files

Author: CrashTestJava

README.md

@@ -39,6 +39,7 @@ a little experiment, so you have six options to approach your idea:
 
 Globals namespaces
   * [app](api/app.md#app)
+  * [app.clipboard](api/app_clipboard.md#appclipboard)
   * [app.command](api/app_command.md#appcommand)
   * [app.fs](api/app_fs.md#appfs)
   * [app.os](api/app_os.md#appos)

api/app_clipboard.md

@@ -0,0 +1,71 @@
+## app.clipboard
+
+A set of functions to handle the clipboard. 
+
+When calling a function with clipboard write access in a script, Aseprite will ask the user if they want to allow the function to run or stop the script. 
+
+![security popup](image/security.png)
+
+## app.clipboard.text
+
+```lua
+local text = app.clipboard.text
+```
+
+Gets or sets the clipboard text. Returns `nil` if there is no text.
+
+## app.clipboard.image
+
+```lua
+local image = app.clipboard.image
+```
+
+Gets or sets the clipboard [image](image.md#image). Returns `nil` if there is no image.
+
+## app.clipboard.content
+
+```lua
+local content = app.clipboard.content
+```
+
+Gets the content of the clipboard, as a table. Values:
+
+* `image`: An [image](image.md#image) object or `nil`
+* `selection`: A [selection](selection.md#selection) object or `nil`
+* `palette`: A [palette](palette.md#palette) object or `nil` 
+* `tileset`: A [tileset](tileset.md#tileset) object or `nil` 
+* `text`: A string or `nil` 
+
+Depending on what is copied, each value will be set differently. Case table:
+
+|             |An image is copied in Aseprite      |An image is copied externally|Text is copied|A portion of the Palette is copied                       |
+|-------------|------------------------------------|-----------------------------|--------------|---------------------------------------------------------|
+|`image`    |[Image](image.md#image)             |[Image](image.md#image)      |`nil`         |`nil`                                                    |
+|`selection`|[Selection](selection.md#selection) |`nil`                        |`nil`         |`nil`                                                    |
+|`palette`  |Sprite [palette](palette.md#palette)|`nil`                        |`nil`         |`nil`                                                    |
+|`tileset`  |`nil`                               |`nil`                        |`nil`         |`nil`                                                    |
+|`text`     |`nil`                               |`nil`                        |String        |String of selected colors in hex codes, seperated by `\n`|
+
+## app.clipboard.hasText
+
+```lua
+local hasText = app.clipboard.hasText
+```
+
+Returns true if the last item copied to the clipboard was text.
+
+## app.clipboard.hasImage
+
+```lua
+local hasImage = app.clipboard.hasImage
+```
+
+Returns true if the last item copied to the clipboard was an [image](image.md#image).
+
+## app.clipboard.clear()
+
+```lua
+app.clipboard.clear()
+```
+
+Clears the clipboard.

api/image/security.png

@@ -5,6 +5,7 @@
 
 Globals namespaces
   * [app](api/app.md#app)
+  * [app.clipboard](api/app_clipboard.md#appclipboard)
   * [app.command](api/app_command.md#appcommand)
   * [app.fs](api/app_fs.md#appfs)
   * [app.os](api/app_os.md#appos)