chore(docs): fix typo (plugion => plugin) in DESIGN_GOALS.md

This PR fixes a typo in `./compiler/docs/DESIGN_GOALS.md`.

I believe `plugion` should be `plugin`.

compiler/docs/DESIGN_GOALS.md

@@ -41,7 +41,7 @@ React Compiler has two primary public interfaces: a Babel plugin for transformin
 
 The core of the compiler is largely decoupled from Babel, using its own intermediate representations. The high-level flow is as follows:
 
-- **Babel Plugin**: Determines which functions in a file should be compiled, based on the plugion options and any local opt-in/opt-out directives. For each component or hook to be compiled, the plugin calls the compiler, passing in the original function and getting back a new AST node which will replace the original.
+- **Babel Plugin**: Determines which functions in a file should be compiled, based on the plugin options and any local opt-in/opt-out directives. For each component or hook to be compiled, the plugin calls the compiler, passing in the original function and getting back a new AST node which will replace the original.
 - **Lowering** (BuildHIR): The first step of the compiler is to convert the Babel AST into React Compiler's primary intermediate representation, HIR (High-level Intermediate Representation). This phase is primarily based on the AST itself, but currently leans on Babel to resolve identifiers. The HIR preserves the precise order-of-evaluation semantics of JavaScript, resolves break/continue to their jump points, etc. The resulting HIR forms a control-flow graph of basic blocks, each of which contains zero or more consecutive instructions followed by a terminal. The basic blocks are stored in reverse postorder, such that forward iteration of the blocks allows predecessors to be visited before successors _unless_ there is a "back edge" (ie a loop).
 - **SSA Conversion** (EnterSSA): The HIR is converted to HIR form, such that all Identifiers in the HIR are updated to an SSA-based identifier.
 - Validation: We run various validation passes to check that the input is valid React, ie that it does not break the rules. This includes looking for conditional hook calls, unconditional setState calls, etc.