chore: add test files for local dev

dev-data/Network_fundamentals.md

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+---
+title: Network_fundamentals
+tags: [networks, network-protocols]
+created: Saturday, August 03, 2024
+---
+
+# Network fundamentals
+
+> A network is a system that allows computing devices to communicate and
+> exchange information with each other.
+
+In order for devices to be able to communicate they must share a common
+**communication protocol**.
+
+A protocol specifies **rules determining how information is to be exchanged**.
+(Simply connecting two devices is not sufficient for them to be able to
+communicate, they must have a shared language.)
+
+The nodes of a network are called [hosts](Network_hosts.md).

dev-data/Peer_to_peer_network.md

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+---
+title: Peer_to_peer_network
+tags: [networks]
+created: Friday, August 09, 2024
+---
+
+# Peer to peer network
+
+A decentralised network model where each participant (peer) acts as both a
+client and a server.
+
+Resources are shared directly between peers rather than being coordinated via a
+server.
+
+Under a server architecture, multiple requests are made from different hosts for
+resources. The server manages this load and is in control of what is being
+shared, to whom, and when. With P2P there is no central authority equivalent to
+this. Each peer both shares and consumes resources and in this sense is both a
+client and a server.
+
+A practical example of this is [torrenting](Torrenting.md) - an applicaton of
+P2P technology to file sharing.
+
+## Benefits
+
+- Decentralisation, no central authority, also means no single point of failure.
+- Scalable: the network capacity grows with the number of users (contrast
+  servers)
+- Efficiency: idle resources of peers are put to use
+- Improved performance for popular content
+
+## Drawbacks
+
+- Security: potential for malicious peers and content
+- Inconsistent availability of resources

dev-data/Turing_completeness.md

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+---
+title: Turing_Completeness
+tags: [theory-of-computation, Turing]
+created: Friday, September 13, 2024
+---
+
+# Turing Completeness
+We know that a [Turing machine](Turing_machines.md) is a theoretical construct
+of a computer that:
+
+> contains mutable state, executes sequences of simple instructions that read
+> and write that state, and can pick different execution paths depending on the
+> state (via conditional branch instructions.)
+
+A Turing Complete (TC) system is a system that abides by, or can be reduced to,
+the above description.
+
+TC also serves as a _definition of computability_ and provides a formal basis
+for conceiving of computation at a theoretical level.
+
+All Turing Complete systems are functionally equivalent. This means they can
+simulate each other given enough time and memory. Similarly a TC system can in
+principle perform any computation that any other programmable computer can
+perform. This is true for _other_ TC systems and also those that are not TC
+however the inverse doesn't hold: a non-TC system cannot emulate a TS system.
+For instance a calculator cannot do what a TC smart phone can do. But a smart
+phone can act as a calculator.
+
+Completeness applies to the hardware of computers as well as their software.
+
+Turing Completeness is the theoretical basis of the practical concept of a
+"general-purpose computer": a general-purpose computer is such because it is
+TC - it can in theory compute anything that is computable.
+
+Most modern programming languages are Turing Complete in that they can, in
+theory, be used to compute anything that is computable.
+
+What about Universal Turing Machines eh?