cnc: Update cloaking, building destroyed sounds

- Use trans1.aud as the cloak sound, on both STNK and cloak
  given from crates

- Use crumble.aud rather than xplobig4.aud for building destruction
adhere to opendesktop menu-spec

Version= is the version of the .desktop file specification!
adhere to SPDX for RPM
increment debian copyright year
[CNC] Chinook priced reduced to $750

Halved Chinook price, $1500 to $750.
Infantry should be a more feasible strategy, and transporting them quickly will make them more usable.
This should be good for Nod especially since they don't have APCs.
Helipad reduced to $1000. Palette order fixed.

Helipad price reduced to $1000. Should make helicopter transports more accessible. Should also make having a few "support helis" flying around a more viable strategy, for non-standard builds.
Fixed palette order to be better grouped and in more progressive order. 
Re-arranged document so that it's sorted better.
use markdown for readme and contributing guidelines

- https://github.com/github/markup
- https://github.com/blog/1184-contributing-guidelines
Shroud creators now only temporarily block explored shroud.
On powerdown or removal from the game, any previously explored terrain will become visible once again.
Enabling mobile gap generators.
Allies 04: Fix multiple waves of spies being able to infiltrate the lab
Clean up Allies 04 yaml. Adjust hero spy reveal range from 5 to 6. Add TRUK as buildable unit
Clamp reveal range to 0-50 in PlayerStatistics to stop crashes for actors with reveal ranges > 50
Use Action<bool> for objective delegate type
Fixed #2651: Units not in world should not be added to the attack force

Otherwise, a pillbox's e1 passenger is counted as part of the attack
force and ends up jamming HackyAI's attack logic until it is destroyed.
[cnc] Obelisk now AutoTargeted by units, etc.

Obelisk of light was missing "-AutoTargetIgnore". All the guard towers have it, but for some reason the Obelisk didn't. 
Update mods/cnc/mod.yaml

Add support for Nyergud's Music Upgrade Pack
[cnc] added names for explosions

Easier-to-understand names for explosions, which can be used in the future. Can phase out old names/numbers slowly.
Also included some explosions from the C&C Content which were not in use and did not have names.
[cnc] inftry detect cloaked in next tile(C&C orig)

Infantry can detect cloaked units in the next tile. This behaviour was in the original C&C Gold.
(Even though it says range=2, it is actually just in the next tile)

Fixed GrenadierExplode.
[cnc] Airstrike cooldown 3 mins. (from 4). tweaks.

Air Strike cooldown time reduced from 4 minutes to 3. (Ion Cannon is 3). [games are short in CNC, and waiting 4 minutes for your first airstrike is a long time.]
HQ's hitpoints reduced to 750, so it can be nuked in one shot. (but not Ion Cannon'd) 
Airfield HP reduced to 1500, so Ion + Airstrike can destroy it. (For some reason, it doesn't die as easily as Weapons Factory, despite having the same HP)
Better error messages when merging duplicate yaml