Update website/docs/reference/manifest.md

Co-authored-by: Wojciech Szymczyk <wojciech.szymczyk@swmansion.com>
Signed-off-by: maciektr <mtratnowiecki@gmail.com>

website/docs/reference/manifest.md

@@ -328,7 +328,7 @@ unstable-add-statements-functions-debug-info = true
 > It may slow down the compilation - it is advised not to use it for other purposes than mentioned in
 > [cairo-coverage](https://github.com/software-mansion/cairo-coverage) documentation.
 
-If enabled, during the project compilation Scarb will a add mapping between Sierra statement indexes and locations in the code to debug info. A statement index maps to a vector consisting of code fragment which caused the statement to be generated and all code fragments that were inlined or generated along the way.
+If enabled, during the project compilation Scarb will add a mapping between Sierra statement indexes and locations in the code to debug info. A statement index maps to a vector consisting of code fragment which caused the statement to be generated and all code fragments that were inlined or generated along the way.
 By default, this flag is disabled.
 
 ```toml