set default minimum number of target sources to 2

CMake/cotire.cmake

@@ -3752,7 +3752,7 @@ else()
 	set (COTIRE_UNITY_SOURCE_EXCLUDE_EXTENSIONS "m;mm" CACHE STRING
 		"Ignore sources with the listed file extensions from the generated unity source.")
 
-	set (COTIRE_MINIMUM_NUMBER_OF_TARGET_SOURCES "3" CACHE STRING
+	set (COTIRE_MINIMUM_NUMBER_OF_TARGET_SOURCES "2" CACHE STRING
 		"Minimum number of sources in target required to enable use of precompiled header.")
 
 	if (NOT DEFINED COTIRE_MAXIMUM_NUMBER_OF_UNITY_INCLUDES_INIT)

MANUAL.md

@@ -324,7 +324,7 @@ directories. A target inherits the property value from its enclosing directory.
 ### disabling precompiled headers for small targets
 
 The cache variable `COTIRE_MINIMUM_NUMBER_OF_TARGET_SOURCES` can be set to the minimum number of
-source files required to enable the use of a precompiled header. It defaults to 3. To override the
+source files required to enable the use of a precompiled header. It defaults to 2. To override the
 default, run `cmake` with the following options:
 
     $ cmake -D COTIRE_MINIMUM_NUMBER_OF_TARGET_SOURCES=5 <path-to-source>