fix invalid reference in documentation

alib2data/src/indexes/stringology/FactorOracleAutomaton.h

alib2data/src/indexes/stringology/PositionHeap.h

alib2data/src/indexes/stringology/SuffixArray.h

alib2data/src/indexes/stringology/SuffixAutomaton.h

alib2data/src/indexes/stringology/SuffixTrie.h

alib2data/src/regexp/formal/FormalRegExp.h

alib2data/src/regexp/unbounded/UnboundedRegExp.h

alib2data/src/string/CyclicString.h

alib2data/src/string/Epsilon.h

alib2data/src/string/LinearString.h

alib2data/src/string/WildcardLinearString.h

alib2data/src/tree/ranked/PostfixRankedTree.h

alib2data/src/tree/ranked/PrefixRankedBarNonlinearPattern.h

alib2data/src/tree/ranked/PrefixRankedBarPattern.h

alib2data/src/tree/ranked/PrefixRankedBarTree.h

alib2data/src/tree/ranked/PrefixRankedNonlinearPattern.h

alib2data/src/tree/ranked/PrefixRankedPattern.h

alib2data/src/tree/ranked/PrefixRankedTree.h

alib2data/src/tree/ranked/RankedNonlinearPattern.h

alib2data/src/tree/ranked/RankedPattern.h