Add documentation for 3 implementations

Author: chenyukang

Makefile

@@ -50,7 +50,9 @@ build:
 			cargo build -p $$(basename $$crate) $(MODE_ARGS) $(CARGO_ARGS); \
 		done; \
 		for contract in $(sort $(wildcard contracts/*)); do \
-			$(MAKE) -e -C $$contract build; \
+			if [ -d "$$contract" ]; then \
+				$(MAKE) -e -C $$contract build; \
+			fi; \
 		done; \
 		for crate in $(wildcard tools/*); do \
 			cargo build -p $$(basename $$crate | tr '-' '_') $(MODE_ARGS) $(CARGO_ARGS); \

README.md

@@ -1,8 +1,8 @@
 # quantum-resistant-lock-script
-Quantum resistant lock script on CKB, based on [NIST FIPS 205](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.205.pdf) standard. 
+Quantum resistant lock script on CKB, based on [NIST FIPS 205](https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.205.pdf) standard.
 
-There are 3 implementations:
 
+There are 3 implementations:
 * [A C lock script](./contracts/c-sphincs-all-in-one-lock/) using [SPHINCS+](https://github.com/sphincs/sphincsplus)
 * [A Rust lock script](./contracts/sphincs-all-in-one-lock/) using [fips205](https://github.com/integritychain/fips205)
 * [A hybrid lock script](./contracts/hybrid-sphincs-all-in-one-lock/) with the implementation of SPHINCS+ utilizing the sphincsplus C library and Rust glue code.