chore: add .gitignore and remove tracked xcuserdata

Xcode user-specific data (xcuserdata) should not be version controlled.

ReadViewDemo/ReadViewDemo.xcworkspace/xcuserdata/shen.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist

@@ -1,36 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<Bucket
-   uuid = "B0633BC4-5BBB-46C3-9C4F-C3B9A25989D3"
-   type = "0"
-   version = "2.0">
-   <Breakpoints>
-      <BreakpointProxy
-         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
-         <BreakpointContent
-            uuid = "7F1DAB5A-519E-47BC-A62E-B330F41132ED"
-            shouldBeEnabled = "Yes"
-            ignoreCount = "0"
-            continueAfterRunningActions = "No"
-            filePath = "../Sources/RDReaderView/EPUBTextRendering/RDEPUBTextBookCache.swift"
-            startingColumnNumber = "9223372036854775807"
-            endingColumnNumber = "9223372036854775807"
-            startingLineNumber = "323"
-            endingLineNumber = "323">
-         </BreakpointContent>
-      </BreakpointProxy>
-      <BreakpointProxy
-         BreakpointExtensionID = "Xcode.Breakpoint.FileBreakpoint">
-         <BreakpointContent
-            uuid = "0313507F-BD79-4B9D-B92F-703991289849"
-            shouldBeEnabled = "Yes"
-            ignoreCount = "0"
-            continueAfterRunningActions = "No"
-            filePath = "../Sources/RDReaderView/EPUBTextRendering/RDEPUBTextBookCache.swift"
-            startingColumnNumber = "9223372036854775807"
-            endingColumnNumber = "9223372036854775807"
-            startingLineNumber = "351"
-            endingLineNumber = "351">
-         </BreakpointContent>
-      </BreakpointProxy>
-   </Breakpoints>
-</Bucket>