docs: update libmdbx links (#3929)

docs/programmers_guide/db_faq.md

@@ -27,8 +27,8 @@ We have Go, Rust and C++ implementations of `RoKV` interface.
 
 Rationale and Architecture of DB interface: [./../../ethdb/Readme.md](../../ethdb/Readme.md)
 
-MDBX docs: [erthink.github.io/libmdbx/](https://erthink.github.io/libmdbx/)
-and [https://github.com/erthink/libmdbx/blob/master/mdbx.h](https://github.com/erthink/libmdbx/blob/master/mdbx.h)
+MDBX: [docs](https://libmdbx.website.yandexcloud.net)
+and [mdbx.h](https://github.com/torquem-ch/libmdbx/blob/master/mdbx.h)
 
 
 ### How RAM used

docs/programmers_guide/dupsort.md

@@ -145,7 +145,7 @@ feature DupFixed (can add this flag to table configuration).
 
 It means in 1 db call you can Get/Put up to 4Kb of sub-table keys.
 
-[mdbx docs](https://github.com/erthink/libmdbx/blob/master/mdbx.h)
+[see mdbx.h](https://github.com/torquem-ch/libmdbx/blob/master/mdbx.h)
 
 Erigon
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