Update README and versioning (#121)

- Reword elements of the README, mostly changing the elements about
   vanilla ComputerCraft.
 - Change versioning scheme: we'll now do 1.x.y, with 1.81.0 being the
   next version.
 - Include MC version in the file name
 - Stop bundling javadoc with the jar. We'll look into hosting this on
   squiddev.cc if really needed.
 - Remove the LuaJ license from the root - we no longer bundle the
   sources, so it's not needed here.

I realise this change looks a little dodgey on its own, so see #113 for
the full rationale.

build.gradle

@@ -25,12 +25,14 @@ apply plugin: 'org.ajoberstar.grgit'
 apply plugin: 'maven-publish'
 apply plugin: 'maven'
 
-version = "1.80pr1.14"
+def mc_version = "1.12.2"
+version = "1.81.0"
+
 group = "org.squiddev"
-archivesBaseName = "cc-tweaked"
+archivesBaseName = "cc-tweaked-${mc_version}"
 
 minecraft {
-    version = "1.12.2-14.23.4.2749"
+    version = "${mc_version}-14.23.4.2749"
     runDir = "run"
     replace '${version}', project.version
 
@@ -86,11 +88,9 @@ jar {
         attributes('FMLAT': 'computercraft_at.cfg')
     }
 
-    into("docs", { from (javadoc.destinationDir) })
-
-    into("api", { from (sourceSets.main.allSource) {
+    from (sourceSets.main.allSource) {
         include "dan200/computercraft/api/**/*.java"
-    }})
+    }
 
     from configurations.shade.collect { it.isDirectory() ? it : zipTree(it) }
 }
@@ -149,7 +149,7 @@ reobfJar.dependsOn proguardMove
 
 processResources {
     inputs.property "version", project.version
-    inputs.property "mcversion", project.minecraft.version
+    inputs.property "mcversion", project.version
 
     def hash = 'none'
     Set<String> contributors = []
@@ -171,7 +171,7 @@ processResources {
         include 'assets/computercraft/lua/rom/help/credits.txt'
 
         expand 'version':project.version,
-               'mcversion':project.minecraft.version,
+               'mcversion':project.version,
                'gitcontributors':contributors.sort(false, String.CASE_INSENSITIVE_ORDER).join('\n')
     }