More user-friendly default value and supplementary explanation for another content

- Modified the opacity of the message box background
- Added some migration information about `ExtendedAircraftMissions`

Author: CrimRecya

docs/User-Interface.md

@@ -408,7 +408,7 @@ In `RA2MD.INI`:
 [Phobos]
 MessageApplyHoverState=false            ; boolean
 MessageDisplayInCenter=false            ; boolean
-MessageDisplayInCenter.BoardOpacity=30  ; integer
+MessageDisplayInCenter.BoardOpacity=40  ; integer
 MessageDisplayInCenter.LabelsCount=6    ; integer
 MessageDisplayInCenter.RecordsCount=12  ; integer
 ```

docs/Whats-New.md

@@ -452,7 +452,7 @@ New:
 - Randomized anims for several behaviors (by Ollerus)
 - Shield respawn animation and weapon (by Ollerus)
 - [Customize the chained damage of the wall](Fixed-or-Improved-Logics.md#customize-the-chained-damage-of-the-wall) (by TaranDahl)
-- Allow the aircraft to enter area guard mission and not crash immediately without any airport (by CrimRecya)
+- Allow the aircraft to enter area guard mission and not crash immediately without any airport. And now when `ExtendedAircraftMissions` is enabled, aircraft that can land at the airport will check at any time to see if they have a dock. Therefore, if there are aircraft in your mission that require dock and you have not provided enough or not disabled the feature, they will crash immediately (by CrimRecya)
 - [Unlimbo Detonate warhead](New-or-Enhanced-Logics.md#unlimbo-detonate-warhead) (by FlyStar)
 - [Attack](New-or-Enhanced-Logics.md#attack-technos-underground) and [damage](New-or-Enhanced-Logics.md#damage-technos-underground) technos underground (by TaranDahl)
 - Fast access structure (by FlyStar)

docs/locale/zh_CN/LC_MESSAGES/User-Interface.po

@@ -1307,14 +1307,14 @@ msgid ""
 "[Phobos]\n"
 "MessageApplyHoverState=false            ; boolean\n"
 "MessageDisplayInCenter=false            ; boolean\n"
-"MessageDisplayInCenter.BoardOpacity=30  ; integer\n"
+"MessageDisplayInCenter.BoardOpacity=40  ; integer\n"
 "MessageDisplayInCenter.LabelsCount=6    ; integer\n"
 "MessageDisplayInCenter.RecordsCount=12  ; integer\n"
 msgstr ""
 "[Phobos]\n"
 "MessageApplyHoverState=false            ; boolean\n"
 "MessageDisplayInCenter=false            ; boolean\n"
-"MessageDisplayInCenter.BoardOpacity=30  ; integer\n"
+"MessageDisplayInCenter.BoardOpacity=40  ; integer\n"
 "MessageDisplayInCenter.LabelsCount=6    ; integer\n"
 "MessageDisplayInCenter.RecordsCount=12  ; integer\n"
 

src/Phobos.INI.cpp

@@ -55,7 +55,7 @@ bool Phobos::Config::EnableSelectBox = false;
 bool Phobos::Config::DigitalDisplay_Enable = false;
 bool Phobos::Config::MessageApplyHoverState = false;
 bool Phobos::Config::MessageDisplayInCenter = false;
-int Phobos::Config::MessageDisplayInCenter_BoardOpacity = 30;
+int Phobos::Config::MessageDisplayInCenter_BoardOpacity = 40;
 int Phobos::Config::MessageDisplayInCenter_LabelsCount = 6;
 int Phobos::Config::MessageDisplayInCenter_RecordsCount = 12;
 bool Phobos::Config::RealTimeTimers = false;
@@ -91,7 +91,7 @@ DEFINE_HOOK(0x5FACDF, OptionsClass_LoadSettings_LoadPhobosSettings, 0x5)
 	Phobos::Config::ShowPlacementPreview = CCINIClass::INI_RA2MD.ReadBool(phobosSection, "ShowPlacementPreview", true);
 	Phobos::Config::MessageApplyHoverState = CCINIClass::INI_RA2MD.ReadBool(phobosSection, "MessageApplyHoverState", false);
 	Phobos::Config::MessageDisplayInCenter = CCINIClass::INI_RA2MD.ReadBool(phobosSection, "MessageDisplayInCenter", false);
-	Phobos::Config::MessageDisplayInCenter_BoardOpacity = CCINIClass::INI_RA2MD.ReadInteger(phobosSection, "MessageDisplayInCenter.BoardOpacity", 30);
+	Phobos::Config::MessageDisplayInCenter_BoardOpacity = CCINIClass::INI_RA2MD.ReadInteger(phobosSection, "MessageDisplayInCenter.BoardOpacity", 40);
 	Phobos::Config::MessageDisplayInCenter_LabelsCount = CCINIClass::INI_RA2MD.ReadInteger(phobosSection, "MessageDisplayInCenter.LabelsCount", 6);
 	Phobos::Config::MessageDisplayInCenter_RecordsCount = CCINIClass::INI_RA2MD.ReadInteger(phobosSection, "MessageDisplayInCenter.RecordsCount", 12);
 	Phobos::Config::RealTimeTimers = CCINIClass::INI_RA2MD.ReadBool(phobosSection, "RealTimeTimers", false);