Update scalar-crypto.adoc

Signed-off-by: Kersten Richter <[email protected]>

src/scalar-crypto.adoc

@@ -120,7 +120,7 @@ in the specification.
 This supporting code is listed in
 <<crypto_scalar_appx_sail>>.
 The 
-link:https://github.com/rems-project/sail/blob/sail2/manual.pdf[Sail Manual]
+link:https://alasdair.github.io/manual.html[Sail Manual]
 is recommended reading in order to best understand the code snippets.
 
 Note that this document contains only a subset of the formal model: refer to
@@ -5343,7 +5343,7 @@ https://github.com/riscv/riscv-crypto
 This section contains the supporting Sail code referenced by the
 instruction descriptions throughout the specification.
 The
-link:https://github.com/rems-project/sail/blob/sail2/manual.pdf[Sail Manual]
+link:https://alasdair.github.io/manual.html[Sail Manual]
 is recommended reading in order to best understand the supporting code.
 
 [source,sail]