* #836 Fix UnsupervisedReadingOrder orders 2 blocks on the same row out of order
Add images for documentation
* Update Documentation: Additional example, Reference to wiki
* Change code formating to C# on documentation
* Fix link in documentation
* Fix Spelling
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Co-authored-by: David <David@david>
* Use a fixed list of operations in ReflectionGraphicsStateOperationFactory rather than searching via reflection.
* Add a unit test to check that ReflectionGraphicsStateOperationFactory.operations contains all supported graphics operations
* Avoid encoding ASCII in more cases
* Make Space a const
* Use WriteWhiteSpace extension to eliminate possible virtual call
* Use ASCII when encoding constrained character subset
* Simplify pragmas
* Revert Whitespace rename
* Fix using statement order
* Remove obsolete serialization support on .NET
* Remove obsolete serialization support on .NET (part 2)
* Make AdobeFontMetricsLigature a struct
* Make AdobeFontMetricsCharacterSize a struct
* Eliminate allocation in CompactFontFormatData
* Pass TransformationMatrix by reference
* Seal Encoding classes
* Make SubTableHeaderEntry a readonly struct
* Introduce StringSplitter and eliminate various allocations in GlyphListFactory
* Eliminate a few substring allocations
* Use char overload on StringBuilder
* Eliminate virtual calls on stringIndex
* Optimize ReadHelper ReadLong and ReadInt methods
* Add additional readonly annotations to PdfRectangle
* Optimize NameTokenizer
* Eliminate allocation in TrueTypeGlyphTableSubsetter
* Use empty arrays
* Eliminate allocations in OperationWriteHelper.WriteHex
* Use simplified DecryptCbc method on .NET 6+
* Fix windows-1252 encoding not working on net6.0 and 8.0
* Update int buffers to exact unsigned max length and eliminate additional byte allocation
* Fix typo
* Remove unused constant
* Throw when trying to inverse a matrix with a determinant of 0
* Optimize Hex.GetString on .NET
* Updates tests for Matrix3x3.Inverse() change
* Eliminate allocation in InternalStringExtensions
* Use vectorized Span.Fill method
* Eliminate various string allocations when parsing numbers
* Remove unused using statements
* Fix Matrix3x3 Equals nullability
* Enable nullable annotations
* Remove unused Jetbrain annotations
* Ensure system using statements are first
* Improve nullability annotations
* Annotate encryptionDictionary is non-null when IsEncrypted is true
* Disable nullable for PdfTokenScanner.Get
* Improve nullability annotations for ObjectLocationProvider.TryGetCached
* Revert changes to RGBWorkingSpace
* Update UglyToad.PdfPig.Package with new framework targets (fixes nightly builds)
