Remove in-process flag (EbookFoundation#9277)

Remove the in-process flag for "A Complete Guide to Standard C++ Algorithms", as the book now has a v1.0.0 release.

Author: HappyCerberus

books/free-programming-books-langs.md

@@ -510,7 +510,7 @@ Books on general-purpose programming that don't focus on a specific language are
 
 ### <a id="cpp"></a>C++
 
-* [A Complete Guide to Standard C++ Algorithms](https://github.com/HappyCerberus/book-cpp-algorithms) - Šimon Tóth (PDF, LaTeX) (:construction: *in process*)
+* [A Complete Guide to Standard C++ Algorithms](https://github.com/HappyCerberus/book-cpp-algorithms) - Šimon Tóth (PDF, LaTeX)
 * [C++ Annotations](https://fbb-git.gitlab.io/cppannotations) - Frank B. Brokken (HTML, PDF)
 * [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md) - `edt.:` Bjarne Stroustrup, Herb Sutter
 * [C++ For Programmers](https://tfetimes.com/wp-content/uploads/2015/04/c-for-c-programmers.pdf) - JT Kalnay (PDF)