Change alpha to beta in micro rdk docs

[randhid]

Description

Changes alpha to beta in micro-rdk docs.

I think this is all that's needed. From my understanding this file is included in a few other places and generates the warning. Will double check when the link is generated.

[viambot]

Overall readability score: 56.2 (🟢 +0)

File	Readability
micro-rdk.md	44.05 (🟢 +0.08)

View detailed metrics

🟢 - Shows an increase in readability
🔴 - Shows a decrease in readability

File	Readability	FRE	GF	ARI	CLI	DCRS
micro-rdk.md	44.05	39.74	10.94	14.1	14.55	9.16
	🟢 +0.08	🟢 +0	🟢 +0	🟢 +0	🟢 +0.06	🟢 +0

Averages:

	Readability	FRE	GF	ARI	CLI	DCRS
Average	56.2	47.78	10.54	12.9	11.95	7.69
	🟢 +0	🟢 +0	🟢 +0	🟢 +0	🟢 +0	🟢 +0

View metric targets

Metric	Range	Ideal score
Flesch Reading Ease	100 (very easy read) to 0 (extremely difficult read)	60
Gunning Fog	6 (very easy read) to 17 (extremely difficult read)	8 or less
Auto. Read. Index	6 (very easy read) to 14 (extremely difficult read)	8 or less
Coleman Liau Index	6 (very easy read) to 17 (extremely difficult read)	8 or less
Dale-Chall Readability	4.9 (very easy read) to 9.9 (extremely difficult read)	6.9 or less

[viambot]

You can view a rendered version of the docs from this PR at https://docs-test.viam.dev/2124/public

[sguequierre]

Thanks rand!!