Nukkit Relicense the project to LGPL

This PR changes the project's license to the GNU Lesser General Public License (LGPL).

The difference between the current license (GPL) and LGPL is that the latter allows a non-LGPL project (such as a plugin licensed under the MIT license) to use and depend on Nukkit. Previously under the GPL license, this meant every plugin also had to be licensed under the GPL otherwise they would be in breach of Nukkit's license.

With the new license, plugin developers can have peace of mind knowing that they can license their plugins under any license they want without fear of getting a DMCA one day.

For this change to happen, every contributor must agree to it. They are all listed below.

If you agree to relicense your contributions under LGPL, please comment "I agree" in the comments below. Thank you.

[x] @MagicDroidX
[x] @SupremeMortal
[ ] @Pub4Game
[x] @Creeperface01
[x] @PetteriM1
[ ] @Snake1999
[x] @wode490390
[ ] @Angelic47
[x] @caoli5288
[x] @MrPowerGamerBR
[x] @fromgate
[x] @Sleepybear
[x] @Tee7even
[x] @KCodeYT
[ ] @NuclearSteven
[x] @boybook
[x] @DaMatrix
[x] @yescallop
[x] @Rover656
[x] @Niall7459
[x] @joserobjr
[x] @Extollite
[x] @fengberd
[ ] @Vrysed
[x] @magicus
[x] @imjack
[x] @solo5star
[ ] @PeratX
[x] @milkice233
[ ] @ItsLucas
[ ] @xpyctum
[x] @SuperMarcus
[x] @alistairwatts
[x] @mepeisen
[x] @kvetinac97
[ ] @HmHmmHm
[x] @ProjectInfinity
[x] @Leonidius20
[x] @lukeeey
[x] @larryTheCoder
[x] @davidboden
[x] @yungtechboy1
[x] @ZenSirzechs
[x] @Yexeed
[x] @grzegorz2047
[x] @JackboyPlay
[x] @hochbaum
[x] @onebone
[ ] @pcbeard
[ ] @nishuzumi
[x] @Iktaniyalol
[ ] @sero583
[x] @BeerMC
[ ] @vzlomka76
[x] @rcsupermanjob
[x] @minecrafter (Note: now known as @astei)
[ ] @ScraM-Team
[x] @Twister915
[x] @LucGamesYT
[x] @colinrgodsey
[x] @Kaooot
[x] @JustTalDevelops
[x] @EinBexiii
[ ] @applqpak
[x] @KisaragiEffective
[x] @Kazzuk
[x] @VegeoStudios
[x] @net32
[x] @StijnSimons
[x] @GoodLucky777
[x] @AlicanCopur
[x] @DanielFallon
[x] @wsj7178
[x] @SergeyDertan
[x] @wgaox
[ ] @Sulfatezzz
[x] @File14
[x] @Erkam246
[x] @ApocalypsjeNL
[x] @lucko
[x] @Flonja
[x] @TwistedAsylumMC
[x] @ConnorLinfoot
[x] @dignissimus
[ ] @YaBoiBalAnce
[ ] @ittaJ
[x] @jungwuk-ryu
[x] @gabeguz
[x] @Liatori-GR
[x] @Smeo00
[x] @Alemiz112
[x] @Camotoy
[x] @VixikHD
[x] @CloudG360
[x] @DenielWorld
[x] @mgadda
[ ] @flaccid
[x] @popkechupki
[x] @Prushka

Off-topic comments may be marked as such

Mar 03 '21 14:03 lukeeey

(extra pings, it didn't seem to work in the original issue?) @Iktaniyalol @sero583 @BeerMC @vzlomka76 @rcsupermanjob @minecrafter (Note: now known as @astei) @ScraM-Team @Twister915 @LucGamesYT @colinrgodsey @Kaooot @JustTalDevelops @EinBexiii @applqpak @KisaragiEffective @Kazzuk @VegeoStudios @net32 @StijnSimons @GoodLucky777 @AlicanCopur @DanielFallon @wsj7178 @SergeyDertan @wgaox @Sulfatezzz @File14 @Erkam246 @ApocalypsjeNL @lucko @Flonja @TwistedAsylumMC @ConnorLinfoot @dignissimus @YaBoiBalAnce @ittaJ @jungwuk-ryu @gabeguz @Liatori-GR @Smeo00 @Alemiz112 @Camotoy @VixikHD @CloudG360 @DenielWorld @mgadda @flaccid @popkechupki @Prushka

Mar 03 '21 14:03 lukeeey

I agree.