CallFrame has broken links to $?FILE and $?LINE, $?FILE and $?LINE do not mention CallFrame

[AlexDaniel]

Both should mention each other properly.

• https://docs.perl6.org/type/CallFrame has broken links to $?FILE and $?LINE
• CallFrame is not mentioned here https://docs.perl6.org/language/variables#Compile-time_variables

[ahalbert]

Link to $?LINE in call frame is https://docs.perl6.org/type/$DOLLAR_SIGN$QUESTION_MARKLINE
when it should be
https://docs.perl6.org/language/variables#index-entry-%24%3FLINE

[JJ]

Links have been changed to https://docs.perl6.org/language/variables#Compile-time_variables