More documentation tweaks

docs/api/apple2-programming-guide.md

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-[< back to index](../README.md)
+[< back to index](../doc_index.md)
 
 ### A note about Apple II
 

docs/api/bbcmicro-programming-guide.md

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+[< back to index](../doc_index.md)
 
 ### A note about BBC Micro
 

docs/api/command-line.md

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+[< back to index](../doc_index.md)
 
 # Command-line options
 

docs/api/commodore-programming-guide.md

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+[< back to index](../doc_index.md)
 
 ### A note about Commodore 64
 

docs/api/cpc-programming-guide.md

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+[< back to index](../doc_index.md)
 
 ### A note about Amstrad CPC
 

docs/api/custom-platform.md

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+[< back to index](../doc_index.md)
 
 ## Adding a custom platform
 

docs/api/famicom-programming-guide.md

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+[< back to index](../doc_index.md)
 
 # Famicom/NES programming guide
 

docs/api/gb-programming-guide.md

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+[< back to index](../doc_index.md)
 
 # Game Boy programming guide
 

docs/api/getting-started.md

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+[< back to index](../doc_index.md)
 
 # Getting started
 

docs/api/lunix-programming-guide.md

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+[< back to index](../doc_index.md)
 
 ### A note about LUnix
 

docs/api/rom-vs-ram.md

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+[< back to index](../doc_index.md)
 
 ### ROM vs RAM targets
 

docs/api/target-platforms.md

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+[< back to index](../doc_index.md)
                                                       
 # Target platforms