modify basic filestructure

It's unclear what's 'basic', so `basic/` notes have been mostly moved.
The remainder became `shell/`.

shell/conditionals.md

@@ -0,0 +1,88 @@
+---
+title: "conditionals"
+tags: [ "basics" ]
+---
+# If statements
+
+Test statement equality as so:
+
+```
+
+read t1
+read t2
+if test $t1 != $t2; then
+	echo 'variables do not match'
+else
+	echo 'variables match'
+fi
+exit 0
+
+```
+
+# Case Structure
+
+These deal with multiple states rather than forking conditions.
+
+Example: 
+
+```
+
+#!/bin/bash
+
+# Simple case demonstration
+
+echo "What's your favourite creature?"
+read CRE
+case $CRE in
+        human | humanoids ) echo "Why is $CRE always standard?"
+;;
+        troll | monsters ) echo "Not exactly known for their character ..."
+;;
+        owlbears | monsters ) echo "Really you're a wizard fan"
+;;
+esac
+```
+
+# While and Until
+This prints from 1 until 9.
+
+```sh
+COUNTER=1
+while [ $COUNTER -lt 2 ]; do
+        > ((COUNTER++))
+        > echo $COUNTER
+> done
+```
+
+There's also 'until', which stops when something is true, rather than keeping going when something is true.
+
+# For
+
+```sh
+for i in $( ls ); do
+> 	du -sh $i
+> done
+```
+
+# Sequences
+
+The sequences tool counts up from X in jumps of Y to number Z.
+
+Count from 1 to 10.
+
+```sh
+seq 10
+```
+
+Count from 4 to 11.
+
+```sh
+seq 4 11
+```
+
+Count from 1 to 100 in steps of 5.
+
+```sh
+seq 1 5 100
+```
+