Replaced Bruce Eckel's Thinking in C++ broken link with new links. Resolves #373

[hanifz-dr1]

Replaced the old broken link for Bruce Eckel's Thinking in C++ with two links for Volumes 1 and 2. Links:

• http://vergil.chemistry.gatech.edu/resources/programming/pdf/TIC2Vone.pdf
• https://web.mit.edu/merolish/ticpp/TicV2.html