docs: add explicit init decision record

docs/design_decisions/explicit_init.rst

@@ -0,0 +1,51 @@
+Explicit initialization of logging
+==================================
+
+.. dec_rec:: Explicit initialization of logging
+   :id: dec_rec__log__explicit_init
+   :status: proposed
+   :context: See below.
+   :decision: TBA
+
+   Provide a library for explicit initialization of logging.
+
+   **Context:**
+
+   Currently there are multiple approaches to logging initialization.
+   Rust frontend configuration is provided as code and requires explicit initialization before any logging starts.
+   C++ configuration is lazily loaded on first use and based on a JSON file with path provided using environment variable.
+
+   This approach discrepancy makes it difficult to manage logging in multi-language environment.
+   Issue can be solved by providing an explicit initialization library.
+
+   Such explicit logging initialization shall:
+
+   - Initialize logging for Rust and C++ environments.
+   - Handle configuration of all sub-components of the logging environment.
+   - Provide interfaces to Rust and C++.
+
+   Examples of use:
+
+   - Initialize logging in Rust application:
+     - Rust logging frontend
+     - C++-based backend
+     - Rust/C++ log bridge
+   - Initialize logging in C++ application utilizing Rust-based libraries:
+     - C++ logging
+     - Rust logging frontend utilized by libraries
+     - C++-based backend
+     - Rust/C++ log bridge
+
+   **Consequences**
+
+   Such change will require design changes to middleware logging.
+
+   In Rust it is a common practice to explicitly initialize logging before any logging starts.
+   This is true to both `score_log` logging frontend and ubiquitous `log` crate that is a defacto standard for logging in Rust.
+
+   Middleware logging library is currently initialized lazily on first use, using JSON config file.
+   It is not possible to perform the initialization operation explicitly.
+
+   **Justification for the Decision**
+
+   Explicit logging initialization will simplify logging initialization in multi-language environments.

docs/index.rst

@@ -80,3 +80,14 @@ Example:
    }
 
 This enables conditional behavior (e.g., choosing `clang-tidy` for C++ or `clippy` for Rust).
+
+Decision records
+----------------
+
+.. TODO: move decision records to proper location once docs are made.
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   design_decisions/explicit_init.rst