docs: fix typos and inaccuracies

Author: jSqqrq1

README.md

@@ -59,7 +59,7 @@ Some clarifications were enabled without protocol releases:
 
 ## Execution Specification (work-in-progress)
 
-The execution specification is a python implementation of Ethereum that prioritizes readability and simplicity. It will accompanied by both narrative and API level documentation of the various components written in markdown and rendered using docc...
+The execution specification is a python implementation of Ethereum that prioritizes readability and simplicity. It will be accompanied by both narrative and API level documentation of the various components written in markdown and rendered using docc...
 
  * [Rendered specification](https://ethereum.github.io/execution-specs/)
 

SECURITY.md

@@ -3,7 +3,7 @@
 ## Overview
 
 While the Ethereum Execution Layer Specification (EELS) is not intended to be a
-production ready client, the software is intended to fully capable of applying
+production ready client, the software is intended to be fully capable of applying
 state transitions for local testing and acts as a point of reference for the
 other Execution Layer (EL) clients. Therefore, a bug in this spec _could_ imply
 a bug in the production clients, though this is not necessarily the case.
@@ -28,7 +28,7 @@ recommend using the [latest version](https://github.com/ethereum/execution-specs
 
 #### Normal Issues
 
-File a issue in GitHub
+File an issue in GitHub
 
 #### Serious Issues