Change license, add Makefile, add image caching control

1 files changed, 12 insertions, 6 deletions

diff --git a/source/know/concept/toffoli-gate/index.md b/source/know/concept/toffoli-gate/index.md
index 9a99e69..23dc81e 100644
--- a/source/know/concept/toffoli-gate/index.md
+++ b/source/know/concept/toffoli-gate/index.md
@@ -16,29 +16,35 @@ of which it returns $$A$$ and $$B$$ unchanged,
 and flips $$C$$ only if both $$A$$ and $$B$$ are true.
 In circuit logic diagrams, its representation is:
 
-{% include image.html file="toffoli.png" width="19%" alt="Toffoli gate symbol" %}
+{% include image.html file="toffoli.png" width="19%"
+    alt="Toffoli gate symbol" %}
 
 This gate is reversible because $$A$$ and $$B$$ are preserved,
 and it is universal because we can make a NAND gate from it:
 
-{% include image.html file="nand.png" width="38%" alt="NAND gate made of Toffoli gate" %}
+{% include image.html file="nand.png" width="38%"
+    alt="NAND gate made of Toffoli gate" %}
 
 A NAND is enough to implement every conceivable circuit.
 That said, we can efficiently implement NOT, AND, and XOR using a single Toffoli gate too.
 Note that NOT is a special case of NAND:
 
-{% include image.html file="not.png" width="32%" alt="NOT gate made of Toffoli gate" %}
+{% include image.html file="not.png" width="32%"
+    alt="NOT gate made of Toffoli gate" %}
 
-{% include image.html file="and.png" width="35%" alt="AND gate made of Toffoli gate" %}
+{% include image.html file="and.png" width="35%"
+    alt="AND gate made of Toffoli gate" %}
 
-{% include image.html file="xor.png" width="35%" alt="XOR gate made of Toffoli gate" %}
+{% include image.html file="xor.png" width="35%"
+    alt="XOR gate made of Toffoli gate" %}
 
 Using these, we can, as an example, make an OR gate
 from three Toffoli gates,
 thanks to the fact that $$A \lor B = \neg (\neg A \land \neg B)$$,
 i.e. OR is NAND of NOT $$A$$ and NOT $$B$$:
 
-{% include image.html file="or.png" width="50%" alt="OR gate made of Toffoli gates" %}
+{% include image.html file="or.png" width="50%"
+    alt="OR gate made of Toffoli gates" %}
 
 Thanks to its reversibility and universality,
 the Toffoli gate is interesting for quantum computing.