qcolor-from-literal: Update documentation to includes more prescise c…

…hecks and fixits

.reuse/dep5

@@ -7,3 +7,6 @@ Files: tests/qcolor-from-literal/*
 Copyright: Alexander Lohnau <[email protected]>
 License: CC0-1.0
 
+Files: docs/checks/README-qcolor-from-literal.md
+Copyright: Alexander Lohnau <[email protected]>
+License: CC0-1.0

docs/checks/README-qcolor-from-literal.md

@@ -1,10 +1,28 @@
 # qcolor-from-literal
 
 Warns when a `QColor` is being constructed from a string literal such as "#RRGGBB".
+Next to the constructor call, this includes QColor::setNamedColor and the static QColor::fromString method.
 This is less performant than calling the ctor that takes `int`s, since it creates temporary `QString`s.
+Also, the pattern is checked in regards to it only containing hexadecimal values and being of a supported length.
 
-Example:
+### Fixits
+This check provides fixits for #RGB, #RRGGBB and #AARRGGBB patterns.
+For QColor object needing more precision, you should manually create a QRgba64 object.
 
-`QColor c("#000000");` // Use QColor c(0, 0, 0) instead
+For example:
+```
+testfile.cpp:92:16: warning: The QColor ctor taking RGB int value is cheaper than one taking string literals [-Wclazy-qcolor-from-literal]
+        QColor("#123");
+               ^~~~~~
+               0x112233
 
-`c.setNamedColor("#001122");` // Use c = QColor(0, 0x11, 0x22) instead
+testfile.cpp:93:16: warning: The QColor ctor taking RGB int value is cheaper than one taking string literals [-Wclazy-qcolor-from-lite
+        QColor("#112233");
+               ^~~~~~~~~
+               0x112233
+
+testfile.cpp:92:16: warning: The QColor ctor taking ints is cheaper than one taking string literals [-Wclazy-qcolor-from-literal]
+        QColor("#9931363b");
+               ^~~~~~~~~~~
+               0x31, 0x36, 0x3b, 0x99
+```