docs: fix bare infinitive 'allow to' in fhdbetween_fhdwithin.Rd and recode-replace.Rd

[LeonidasZhak]

Summary

Fixed two instances of the bare infinitive grammatical error "allow to" in collapse documentation.

Problem

The verb "allow" requires a gerund (allow + -ing) or a noun phrase before "to" (allow + someone + to). Two Rd files contain the bare infinitive error "allow to":

1. fhdbetween_fhdwithin.Rd line 33: "allow to predict" — bare infinitive error
2. recode-replace.Rd line 100: "allows to remove" — bare infinitive error

Fix

File	Line	Before	After
man/fhdbetween_fhdwithin.Rd	33	"allow to predict"	"allow predicting"
man/recode-replace.Rd	100	"allows to remove"	"allows removing"

Files Changed

File	Lines Changed	Type
man/fhdbetween_fhdwithin.Rd	1	Documentation
man/recode-replace.Rd	1	Documentation
Total	2

Validation

• tools::checkRd('man/fhdbetween_fhdwithin.Rd') — passes (no output = no errors)
• tools::checkRd('man/recode-replace.Rd') — passes (no output = no errors)
• Change is purely documentation (no code changes)

Duplicate Check

• No existing branch or PR addresses bare infinitive in fhdbetween_fhdwithin.Rd or recode-replace.Rd
• No other PRs touch these lines

Stata Migration Relevance

The fhdbetween/fhdwithin functions are powerful tools for high-dimensional linear prediction problems involving large factors and datasets. They are particularly useful for Stata users migrating to R, as they provide an efficient alternative to Stata's areg and xtreg commands for fixed effects models. The HDB and HDW operators add formula support similar to Stata's factor variable notation. Clear documentation helps Stata users understand these advanced features.

The recode-replace.Rd documentation describes functions for recoding and replacing values, which is a common data cleaning operation for Stata users. Stata's recode and replace commands are frequently used, and clear documentation of the collapse equivalents helps Stata users transition to R.

[LeonidasZhak]

Withdrawing this small automated PR while I consolidate an oversized batch of contributions and reduce maintainer review burden. Sorry for the noise, and thank you for maintaining the project.