Add PE detection rule for ImGui

Add new rule db/PE/library_ImGui.4.sg to detect the ImGui library in PE files. The rule marks a match if the library name contains "imgui" or if exported functions start with "ImGui" (sets sOptions to "static" for EAT). Includes author/contact metadata.

db/PE/library_ImGui.4.sg

@@ -0,0 +1,20 @@
+// Detect It Easy: detection rule file
+
+// Author: DosX
+// E-Mail: collab@kay-software.ru
+// GitHub: https://github.com/DosX-dev
+// Telegram: @DosX_dev
+
+// https://github.com/ocornut/imgui
+meta("library", "ImGui");
+
+function detect() {
+    if (PE.isLibraryPresentExp(/imgui/i)) {
+        bDetected = true;
+    } else if (PE.isExportFunctionPresentExp(/^ImGui/)) {
+        sOptions = "static"; // EAT
+        bDetected = true;
+    }
+
+    return result();
+}