Update root-level README and reorganize sources

In an effort to mitigate questions from new, inexperienced users on how
to import data into Fight Club 5e, I rewrote and reorganized the
root-level README file to include detailed instructions on how to
compile their own compendiums using the sources found within this
repository. Some existing data, such as how to create your own
collection file, was moved into other READMEs under the Collections and
Sources directories.

I also took some liberty in reorganizing the directory structure of this
repository and renamed some of the top-level directories. In my view,
having sources under the "FightClub5eXML" folder didn't make a lot of
sense, so I moved those sources into the top-level "Sources" folder. I
made sure to update all of the collection files, along with the
"travis.yml" config file, to properly point to the correct folders.

Finally, while updating the "travis.yml" config file, I changed the
output folder of those build compendiums to be under a top-level
"Compendiums" folder. This folder is ignored by git.

Sources/ExplorersGuideToWildemount/vehicles-dd.xml

@@ -0,0 +1,48 @@
+<?xml version='1.0' encoding='utf-8'?>
+<compendium version="5" auto_indent="NO">
+    <monster>
+      <name>Stahlmaster</name>
+    <size>L</size>
+    <type>CREATURE</type>
+    <alignment>Unaligned</alignment>
+    <ac>16 (natural armor)</ac>
+    <hp>67 (9d10+18)</hp>
+    <speed>walk 30 ft.</speed>
+    <str>18</str>
+    <dex>10</dex>
+    <con>14</con>
+    <int>0</int>
+    <wis>0</wis>
+    <cha>0</cha>
+    <save></save>
+    <skill></skill>
+    <languages></languages>
+    <cr></cr>
+    <resist></resist>
+    <immune>poison, psychic</immune>
+    <vulnerable></vulnerable>
+    <conditionImmune>blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, poisoned, unconscious</conditionImmune>
+    <senses></senses>
+    <trait>
+        <name>Pilot</name>
+      <text>The Stahlmaster requires a Medium humanoid to pilot it. While inside the Stahlmaster, the pilot uses the vehicle's speed and action options and can't take reactions or use bonus actions, and the pilot has total cover. If the Stahlmaster drops to 0 hit points, the pilot is ejected from it and lands prone in an unoccupied space within 5 feet of the vehicle.</text>
+      </trait>
+    <action>
+        <name>Multiattack</name>
+      <text>The Stahlmaster makes two melee attacks, or one melee attack and one ranged attack.</text>
+      </action>
+    <action>
+        <name>Slam</name>
+      <text>Melee Weapon Attack: +6 to hit, reach 5 ft., one target. 9 (1d10 + 4) bludgeoning damage.</text>
+      <attack>Slam|+6|1d10+4</attack>
+      </action>
+    <action>
+        <name>Shoulder-Mounted Crossbow</name>
+      <text>Ranged Weapon Attack: +2 to hit, range 30/120 ft., one target. 6 (1d12) piercing damage.</text>
+      <attack>Shoulder-Mounted Crossbow|+2|1d12</attack>
+      </action>
+    <description>
+Source: Wildemount: Dangerous Designs p. 235</description>
+    <environment></environment>
+    </monster>
+  </compendium>