Add doc for build_info()

Author: aedart

docs/+current/modules/debug/build_info.md

@@ -0,0 +1,36 @@
+---
+title: Build Info
+description: Using git_find_version_tag
+keywords: debug, debugging, build info, cmake
+author: RSP Systems A/S
+---
+
+# Build Info
+
+The `build_info()` function dumps build information about the current build.
+It accepts the following parameter:
+
+* < mode >: (_option_), _cmake [message mode](https://cmake.org/cmake/help/latest/command/message.html#general-messages), e.g. `WARNING`, `NOTICE`, `STATUS`, ...etc._
+  _Defaults to `NOTICE` is mode is not specified._
+* `OUTPUT`: (_optional_), _output variable. If specified, message is assigned to variable, instead of being printed to `stdout` or `stderr`._
+
+## Example
+
+```cmake
+set(LIB_TYPE "SHARED")
+
+build_info()
+```
+
+Outputs a message similar to this (_not all properties are shown in example_):
+
+```txt
+build info:
+ Type: Debug
+ Library Type: SHARED
+ Compiler flags: ...
+ Compiler cxx debug flags: ... 
+ Compiler cxx release flags: ...
+ Compiler cxx min size flags: ...
+ Compiler cxx flags: ...
+```